Mergers from April 1, 1999 to Present

• On January 1, 2001 - The town of Kurosaki from Nishikanbara District
  Nishikanbara District, Niigata
  is a district located in Niigata, Japan.As of March 20, 2006, the district has an estimated population of 8,537. The total area is 25.22 km².- Towns and villages :On March 20, 2006, the towns of Bunsui and Yoshida merged with the former city of Tsubame...
  
   was amagalated into the city of Niigata
  Niigata, Niigata
  is the capital and the most populous city of Niigata Prefecture, Japan. It lies on the northwest coast of Honshu, the largest island of Japan, and faces the Sea of Japan and Sado Island....
  
  .

• On July 7, 2003 - The town of Toyoura from Kitakanbara District
  Kitakanbara District, Niigata
  is a district located in Niigata, Japan. As of April 1, 2005, the district has an estimated population of 13,528. The total area is 37.99 km². The district has one town: Seirō.- History :...
  
   was amagalated into the city of Shibata
  Shibata, Niigata
  is a city located in Niigata, Japan.As of 2008, the city has an estimated population of 103,101 and the density of 194 persons per km². The total area is 532.82 km².The city was founded on January 1, 1947....
  
  .

• On March 1, 2004 - The city of Ryōtsu
  Ryotsu, Niigata
  Ryōtsu was a city located in Niigata Prefecture, Japan.In the year 2003, the city had an estimated population of 16,710 and a density of 71.60 persons per km². The total area was 233.37 km².The city was founded on November 3, 1954...
  
   merged with all towns and villages within Sado District
  Sado District, Niigata
  Sado District was a district in Niigata Prefecture, Japan.The district dissolved on March 2004 when the district merged with the city of Ryōtsu to form the city of Sado.It also contained the following towns and villages:*Aikawa *Kanai...
  
   (the towns of Aikawa, Kanai, Sawata, Hatano, Mano, Hamochi and Ogi; and the villages of Niibo, and Akadomari) to form the city of Sado
  Sado, Niigata
  is a city located on Sado Island in Niigata Prefecture, in the Chūbu region of Japan. Since 2004, the city has comprised the entire island, although not all of its total area of 855.26 km2 is urbanized...
  
  . Sado District
  Sado District, Niigata
  Sado District was a district in Niigata Prefecture, Japan.The district dissolved on March 2004 when the district merged with the city of Ryōtsu to form the city of Sado.It also contained the following towns and villages:*Aikawa *Kanai...
  
   was dissolved with this merger.

• On April 1, 2004 - The towns of Suibara and Yasuda and the villages of Kyogase and Sasakami (all from Kitakanbara District
  Kitakanbara District, Niigata
  is a district located in Niigata, Japan. As of April 1, 2005, the district has an estimated population of 13,528. The total area is 37.99 km². The district has one town: Seirō.- History :...
  
  ) merged to form the city of Agano
  Agano, Niigata
  is a city located in Niigata Prefecture, Japan. As of April 1, 2011, it has an area of 192.72 km² and a population of 46,056 with 13,794 households, and a population density of 239.00 persons per km².-History:...
  
  .

• On November 1, 2004 - The towns of Muika
  Muika, Niigata
  was a town located in Minami-Uonuma District, Niigata, Japan.As of 2003, the town had an estimated population of 28,687 and a density of 108.75 persons per km². The total area was 263.79 km²....
  
   and Yamato
  Yamato, Niigata
  Yamato was a town located in Minamiuonuma District, Niigata, Japan.The town was established as a village in 1956, and promoted to a town in 1962.As of 2003, the town had an estimated population of 15,195 and a density of 116.07 persons per km²...
  
   from Minamiuonuma District
  Minamiuonuma District, Niigata
  is a district located in Niigata, Japan.As of 2003, the district has an estimated population of 72,908 and a density of 77.41 persons per km². The total area is 941.82 km².- Mergers :...
  
   merged to form the city of Minamiuonuma
  Minamiuonuma, Niigata
  is a city located in Niigata Prefecture, Japan. It has an area of 584.82 km² and a population of 62,733 .-History:*The city was established on November 1, 2004 in a merger of the towns Muikamachi and Yamato, both from Minami-Uonuma District, Niigata.*On October 1, 2005, the town of Shiozawa...
  
  .

• On November 1, 2004 - The towns of Horinouchi
  Horinouchi, Niigata
  Horinouchi was a town located in Kitauonuma District, Niigata, Japan.As of 2003, the town was estimated population of 9,403 and a density of 136.28 persons per km²...
  
   and Koide
  Koide, Niigata
  was a town located in Kitauonuma District, Niigata, Japan. It is famous for its snowy ski resort.As of 2003, the town had an estimated population of 12,735 and a density of 423.93 persons per km²...
  
   and the villages of Hirokami
  Hirokami, Niigata
  Hirokami was a village located in Kitauonuma District, Niigata, Japan.As of 2003, the village had an estimated population of 8,892 and a density of 84.17 persons per km²...
  
  , Irihirose
  Irihirose, Niigata
  Irihirose was a village located in Kitauonuma District, Niigata, Japan.As of 2003, the village had an estimated population of 1,907 and a density of 7.01 persons per km²...
  
  , Sumon
  Sumon, Niigata
  Sumon was a village located in Kitauonuma District, Niigata, Japan.As of 2003, the village had an estimated population of 4,663 and a density of 38.85 persons per km²...
  
   and Yunotani
  Yunotani, Niigata
  Yunotani was a village located in Kitauonuma District, Niigata, Japan.As of 2003, the village had an estimated population of 6,433 and a density of 18.38 persons per km²...
  
   (all from Kitauonuma District
  Kitauonuma District, Niigata
  was a district located in Niigata, Japan.- History :* On 1954, areas now covering Ojiya merged and gained city status.* On November 1, 2004 towns of Horinouchi and Koide, and the villages of Hirokami, Irihirose, Sumon and Yunotani merged to create the new city of Uonuma; leaving the village of...
  
  ) merged to form the city of Uonuma
  Uonuma, Niigata
  is a city located in Niigata Prefecture, Japan. It has an area of 946.93 km² and a population of 41,894 .It is famous for its rice – the koshihikari rice grown in Uonuma is the most sought-after and most expensive rice in Japan...
  
  .

• On January 1, 2005 - The town of Yasuzuka
  Yasuzuka, Niigata
  was a town located in Higashikubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 3,521 and a density of 50.14 persons per km²...
  
   and the villages of Maki
  Maki, Niigata (Kubiki)
  Maki was a village located in the Higashikubiki District, Niigata, Japan. The town had no special relationship with another Maki in the same prefecture.The village was established in 1901 by merging Kawabe, Kawakami, and Kunimi Villages....
  
  , Ōshima
  Oshima, Niigata
  was a village located in Higashikubiki District, Niigata, Japan.As of 2003, the village had an estimated population of 2,312 and a density of 32.27 persons per km²...
  
   and Uragawara
  Uragawara, Niigata
  Uragawara was a village located in Higashikubiki District, Niigata, Japan.As of 2003, the village had an estimated population of 4,095 and a density of 80.86 persons per km²...
  
   (all from Higashikubiki District
  Higashikubiki District, Niigata
  Higashikubiki was a district located in Niigata, Japan. The district was founded when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District...
  
  ); the towns of Itakura
  Itakura, Niigata
  Itakura was a town located in Nakakubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 7,526 and a density of 113.16 persons per km²...
  
  , Kakizaki
  Kakizaki, Niigata
  Kakizaki was a town located in Nakakubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 11,649 and a density of 136.42 persons per km²...
  
  , Ōgata
  Ogata, Niigata
  was a town located in Nakakubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 10,636 and a density of 651.72 persons per km²...
  
   and Yoshikawa
  Yoshikawa, Niigata
  Yoshikawa was a town located in Nakakubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 5,253 and a density of 68.57 persons per km²...
  
   and the villages of Kiyosato
  Kiyosato, Niigata
  Kiyosato was a village located in Nakakubiki District, Niigata, Japan.On January 1, 2005 Kiyosato, along with the town of Yasuzuka, the villages of Maki, Ōshima and Uragawara, all from Higashikubiki District, the towns of Itakura, Kakizaki, Ōgata and Yoshikawa, the villages of Kubiki, Nakagō and...
  
  , Kubiki
  Kubiki, Niigata
  Kubiki was a village located in Nakakubiki District, Niigata, Japan.As of 2003, the village had an estimated population of 9,691 and a density of 252.76 persons per km²...
  
  , Nakagō and Sanwa
  Sanwa, Niigata
  Sanwa was a village located in Nakakubiki District, Niigata, Japan.As of 2003, the village had an estimated population of 6,191 and a density of 157.29 persons per km²...
  
   (all from Nakakubiki District
  Nakakubiki District, Niigata
  Nakakubiki was a district located in Niigata, Japan. The district was founded in 1878, when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District...
  
  ); and the town of Nadachi
  Nadachi, Niigata
  was a town located in Nishikubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 3,229 and a density of 48.97 persons per km²...
  
   from Nishikubiki District
  Nishikubiki District, Niigata
  Nishikubiki was a district located in Niigata, Japan. The district was founded in 1878, when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District. At the time of founding, the district covered the city of Itoigawa and the Nadachi District in...
  
   were all merged into the city of Jōetsu
  Joetsu, Niigata
  is a city located in Niigata Prefecture, Japan.As of June 1, 2011, the city has an estimated population of 205,521, with 72,982 households and a population density of 211.15 persons per km². The total area is 973.32 km²....
  
  .

• On March 19, 2005 - The old city of Itoigawa
  Itoigawa, Niigata
  is a city located in rustic southern Niigata Prefecture, Japan.As of 2008, the city has an estimated population of 48,653 and the density of 65.2 persons per km². The total area is 746.24 km².The city was founded on June 1, 1954...
  
   merged with the remaining parts of Nishikubiki District
  Nishikubiki District, Niigata
  Nishikubiki was a district located in Niigata, Japan. The district was founded in 1878, when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District. At the time of founding, the district covered the city of Itoigawa and the Nadachi District in...
  
   (the towns of Nō and Ōmi) to form the new city of Itoigawa
  Itoigawa, Niigata
  is a city located in rustic southern Niigata Prefecture, Japan.As of 2008, the city has an estimated population of 48,653 and the density of 65.2 persons per km². The total area is 746.24 km².The city was founded on June 1, 1954...
  
  . Nishikubiki District
  Nishikubiki District, Niigata
  Nishikubiki was a district located in Niigata, Japan. The district was founded in 1878, when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District. At the time of founding, the district covered the city of Itoigawa and the Nadachi District in...
  
   was dissolved by this action.

• On March 21, 2005 - The city of Niitsu
  Niitsu, Niigata
  was a city located in Niigata, Japan.As of 2003, the city has an estimated population of 66,058 and the density of 843.87 persons per km². The total area is 78.28 km².The city was founded on January 1, 1951...
  
  , Shirone
  Shirone, Niigata
  was a city located in Niigata, Japan.As of 2003, the city had an estimated population of 39,966 and density of 518.63 persons per km². The total area was 77.06 km².The city was founded on June 1, 1959...
  
   and Toyosaka
  Toyosaka, Niigata
  Toyosaka was a city located in Niigata, Japan.As of 2003, the city had an estimated population of 49,159 and the density of 639.67 persons per km². The total area was 76.85 km².The city was founded on November 1, 1970...
  
  , the towns of Kameda
  Kameda, Niigata
  Kameda was a town located in Nakakanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 32,386 and a density of 1,925.45 persons per km²...
  
  , Kosudo
  Kosudo, Niigata
  was a town located in Nakakanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 10,256 and a density of 606.5 persons per km²...
  
   and Yokogoshi
  Yokogoshi, Niigata
  was a town located in Nakakanbara District, Niigata, Japan.In 2003, the town had an estimated population of 11,339 and a density of 480.06 per km²...
  
   from Nakakanbara District
  Nakakanbara District, Niigata
  Nakakanbara was a district located in Niigata Prefecture, Japan.-History:In 1878, Nakakanbara District was established.The district started to shrink after the town of Nuttary merged and Niigata continued to absorb the district...
  
   and the town of Nishikawa
  Nishikawa, Niigata
  Nishikawa was a town located in Nishikanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 12,277 and a density of 495.84 persons per km²...
  
   and the villages of Ajikata
  Ajikata, Niigata
  Ajikata was a village located in Nishikanbara District, Niigata, Japan.As of 2005, the village had an estimated population of 4,506 and a density of 312.05 persons per km²...
  
  , Iwamuro
  Iwamuro, Niigata
  was a village located in the former Nishikanbara District, Niigata, Japan. The area is famous for onsen near Yahiko mountain. Farming remains the predominant industry in the area...
  
  , Katahigashi
  Katahigashi, Niigata
  Katahigashi was a village located in Nishikanbara District, Niigata, Japan.As of 2003, the village had an estimated population of 6,347 and a density of 264.90 persons per km²...
  
  , Nakanokuchi
  Nakanokuchi, Niigata
  was a village located in Nishikanbara District, Niigata, Japan.On March 21, 2005 Nakanokuchi, along with the towns of Kameda, Kosudo and Yokogoshi, all from Nakakanbara District, the town of Nishikawa, the villages of Ajikata, Iwamuro, Katahigashi and Tsukigata, all from Nishikanbara District, and...
  
   and Tsukigata
  Tsukigata, Niigata
  Tsukigata was a village located in Nishikanbara District, Niigata, Japan.On March 21, 2005 Tsukigata, along with the towns of Kameda, Kosudo and Yokogoshi, all from Nakakanbara District, the town of Nishikawa, the villages of Ajikata, Iwamuro, Katahigashi and Nakanokuchi, all from Nishikanbara...
  
   from Nishikanbara District
  Nishikanbara District, Niigata
  is a district located in Niigata, Japan.As of March 20, 2006, the district has an estimated population of 8,537. The total area is 25.22 km².- Towns and villages :On March 20, 2006, the towns of Bunsui and Yoshida merged with the former city of Tsubame...
  
   were all merged into the city of Niigata
  Niigata, Niigata
  is the capital and the most populous city of Niigata Prefecture, Japan. It lies on the northwest coast of Honshu, the largest island of Japan, and faces the Sea of Japan and Sado Island....
  
  .

• On April 1, 2005 - The remaining parts of Nakakubiki District
  Nakakubiki District, Niigata
  Nakakubiki was a district located in Niigata, Japan. The district was founded in 1878, when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District...
  
   (dissolved by this action) - the town of Myōkōkōgen
  Myokokogen, Niigata
  Myōkōkōgen was a town located in Nakakubiki District, Niigata, Japan.In 1916, Myōkō Kōgen became nationally famous when it came first in a vote taken to find the most popular summer resort in Japan....
  
   and the village of Myōkō
  Myoko, Niigata (village)
  Myōkō was a village located in Nakakubiki District, Niigata, Japan.As of 2003, the village had an estimated population of 4,918 and a density of 34.92 persons per km². The total area was 140.82 km²....
  
   were merged into the city of "Arai". Arai changed its name to Myōkō at the same time.

• On April 1, 2005 - The town of Oguni
  Oguni, Niigata
  Oguni was a town located in Kariwa District, Niigata, Japan.As of 2003, the town had an estimated population of 7,044 and a density of 81.76 persons per km²...
  
   from Kariwa District
  Kariwa District, Niigata
  is a district located in Niigata, Japan.As of April 1, 2005, the district has an estimated population of 4,836 and a density of 184.02 persons per km². The total area is 26.28 km²....
  
  , the village of Yamakoshi
  Yamakoshi, Niigata
  Yamakoshi was a village located in Koshi District, Niigata, Japan.As of 2003, the village had an estimated population of 2,035 and a density of 51.09 persons per km²...
  
   from Koshi District
  Koshi District, Niigata
  Koshi was a district located in Niigata, Japan.As of 2003, the district had an estimated population of 2,035 and a density of 51.09 persons per km². The total area is 39.83 km².-Merger and dissolution:...
  
  , the town of Nakanoshima
  Nakanoshima, Niigata
  Nakanoshima was a town located in Minamikanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 12,503 and a density of 293.84 persons per km²...
  
   from Minamikanbara District
  MinamiKanbara District, Niigata
  is a district located in Niigata, Japan.When the district was formed back in the Meiji Period, the district covered the cities of Sanjō and Mitsuke, the town of Tagami, and parts of Kamo and the northern part of Nagaoka....
  
   and the towns of Koshiji
  Koshiji, Niigata
  Koshiji was a town located in Santō District, Niigata, Japan.As of 2003, the town had an estimated population of 14,160 and a density of 242.30 persons per km²...
  
   and Mishima
  Mishima, Niigata
  Mishima was a town located in Santō District, Niigata, Japan.As of 2003, the town has an estimated population of 7,535 and a density of 206.61 persons per km²...
  
   from Santō District
  Santo District, Niigata
  is a district located in Niigata, Japan.- History :* Before the Edo Period, Santō District was part of the now-defunct Koshi District.* On April 1, 2005 the towns of Koshiji and Mishima merged into the city of Nagaoka....
  
   merged into the city of Nagaoka
  Nagaoka, Niigata
  is a city located in the central part of Niigata Prefecture, Japan. It is the second largest city in the prefecture, behind the capital city of Niigata...
  
  . Koshi District
  Koshi District, Niigata
  Koshi was a district located in Niigata, Japan.As of 2003, the district had an estimated population of 2,035 and a density of 51.09 persons per km². The total area is 39.83 km².-Merger and dissolution:...
  
   was thereby dissolved.

• On April 1, 2005 - The old city of Tōkamachi
  Tokamachi, Niigata
  is a city located in Niigata Prefecture, Japan.As of November 31, 2010, the new city has an estimated population of 60,164. The total area of the new city is 589.92 km², including the post-Creation undefined boundary areas....
  
   merged with the towns of Matsudai
  Matsudai, Niigata
  was a town located in Higashikubiki District, Niigata, Japan.As of 2003, the town had an estimated population of 4,016 and a density of 44.39 persons per km²...
  
   and Matsunoyama
  Matsunoyama, Niigata
  was a town located in Niigata Prefecture, Japan.As of 2003, the town had an estimated population of 2,974 and a density of 34.46 persons per km². The total area was 86.31 km²....
  
   from Higashikubiki District
  Higashikubiki District, Niigata
  Higashikubiki was a district located in Niigata, Japan. The district was founded when the former Kubiki District split into Higashikubiki District, Nakakubiki District, and Nishikubiki District...
  
   (dissolved by this merger) and the town of Kawanishi
  Kawanishi, Niigata
  Kawanishi was a town located in Nakauonuma District, Niigata, Japan.As of 2003, the town had an estimated population of 7,829 and a density of 106.44 persons per km²...
  
   and the village of Nakasato
  Nakasato, Niigata
  Nakasato was a village located in Nakauonuma District, Niigata, Japan.As of 2003, the village had an estimated population of 6,171 and a density of 47.85 persons per km²...
  
   from Nakauonuma District
  Nakauonuma District, Niigata
  is a district located in Niigata, Japan.As of April 1, 2005, the district has a population of 11,754. The area is now 372.80 km².The district has one village*Tsunan-History:...
  
   to create the new city of Tōkamachi
  Tokamachi, Niigata
  is a city located in Niigata Prefecture, Japan.As of November 31, 2010, the new city has an estimated population of 60,164. The total area of the new city is 589.92 km², including the post-Creation undefined boundary areas....
  
  .

• On April 1, 2005 - All municipalities within Higashikanbara District
  Higashikanbara District, Niigata
  is a district located in Niigata, Japan.As of March 31, 2006, the district has an estimated population of 15,169 and a density of 15.92 persons per km²...
  
   (Kamikawa
  Kamikawa, Niigata
  was a village located in Higashikanbara District, Niigata, Japan.As of 2003, the village had an estimated population of 3,216 and a density of 8.91 persons per km². The total area was 361.13 km²....
  
  , Kanose
  Kanose, Niigata
  was a town located in Higashikanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 2,753 and a density of 10.68 persons per km²...
  
  , Mikawa
  Mikawa, Niigata
  Mikawa was a village located in Higashikanbara District, Niigata, Japan.As of 2003, the village had an estimated population of 4,116 and a density of 16.47 persons per km². The total area was 249.87 km²....
  
  , and Tsugawa
  Tsugawa, Niigata
  Tsugawa was a town located in Higashikanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 5,000 and a density of 59.39 persons per km². The total area was 84.19 km²....
  
  ) merged to form the town of Aga
  Aga, Niigata
  is a town located in Higashikanbara District, Niigata Prefecture, Japan. It has an area of 952.88 km² and a population of 13,865 as of April 1, 2008...
  
  .

• On May 1, 2005 - The towns of Nishiyama
  Nishiyama, Niigata
  Nishiyama was a town located in Kariwa District, Niigata, Japan.As of 2003, the town had an estimated population of 6,712 and a density of 118.52 persons per km². The total area was 56.63 km²....
  
   and Takayanagi
  Takayanagi, Niigata
  Takayanagi was a town located in Kariwa District, Niigata, Japan.As of 2003, the town had an estimated population of 2,293 and a density of 35.48 persons per km². The total area was 64.63 km²....
  
   from Kariwa District
  Kariwa District, Niigata
  is a district located in Niigata, Japan.As of April 1, 2005, the district has an estimated population of 4,836 and a density of 184.02 persons per km². The total area is 26.28 km²....
  
   were merged into the city of Kashiwazaki
  Kashiwazaki, Niigata
  is a city located in Niigata, Japan.As of May 1, 2008, the city has an estimated population of 92,947 and the density of 210 persons per km². The total area is 442.70 km²....
  
  .

• On May 1, 2005 - The town of Shiunji
  Shiunji, Niigata
  was a town located in Kitakanbara District, Niigata, Japan.On May 1, 2005 Shiunji, along with the village of Kajikawa, also from Kitakanbara District, was merged into the city of Shibata....
  
   and the village of Kajikawa
  Kajikawa, Niigata
  Kajikawa was a village located in Kitakanbara District, Niigata, Japan.On May 1, 2005 Kajikawa, along with the town of Shiunji, also from Kitakanbara District, was merged into the city of Shibata....
  
   from Kitakanbara District
  Kitakanbara District, Niigata
  is a district located in Niigata, Japan. As of April 1, 2005, the district has an estimated population of 13,528. The total area is 37.99 km². The district has one town: Seirō.- History :...
  
   were merged into the city of Shibata
  Shibata, Niigata
  is a city located in Niigata, Japan.As of 2008, the city has an estimated population of 103,101 and the density of 194 persons per km². The total area is 532.82 km².The city was founded on January 1, 1947....
  
  .

• On May 1, 2005 - The city of Sanjō
  Sanjo, Niigata
  is a city located in central part of Niigata, Japan. The city has a Jōetsu Shinkansen stop at Tsubame-Sanjō Station.- Geography :Sanjō is located in the center of Niigata prefecture. It is about 2 hours from Tokyo by way of the Jōetsu Shinkansen or 4 hours on the Kan-Etsu Expressway and Hokuriku...
  
   merged with the town of Sakae
  Sakae, Niigata
  Sakae was a town located in Minamikanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 11,656 and a density of 257.76 persons per km². The total area was 45.22 km²....
  
   and the village of Shitada
  Shitada, Niigata
  Shitada was a village located in Minamikanbara District, Niigata, Japan.As of 2003, the village had an estimated population of 11,118 and a density of 35.75 persons per km². The total area was 311.00 km²....
  
   (both from Minamikanbara District
  MinamiKanbara District, Niigata
  is a district located in Niigata, Japan.When the district was formed back in the Meiji Period, the district covered the cities of Sanjō and Mitsuke, the town of Tagami, and parts of Kamo and the northern part of Nagaoka....
  
  ) to create the city of Sanjō
  Sanjo, Niigata
  is a city located in central part of Niigata, Japan. The city has a Jōetsu Shinkansen stop at Tsubame-Sanjō Station.- Geography :Sanjō is located in the center of Niigata prefecture. It is about 2 hours from Tokyo by way of the Jōetsu Shinkansen or 4 hours on the Kan-Etsu Expressway and Hokuriku...
  
  .

• On September 1, 2005 - The towns of Nakajō
  Nakajo, Niigata
  Nakajō was a town located in Kitakanbara District, Niigata, Japan. Nakajo is now part of Tainai.As of 2003, the town had an estimated population of 27,026 and a density of 319.53 persons per km²...
  
   and Kurokawa
  Kurokawa, Niigata
  Kurokawa was a village located in Kitakanbara District, Niigata, Japan.As of 2003, the village had an estimated population of 6,577 and a density of 36.42 persons per km². The total area was 180.60 km²....
  
   (both from Kitakanbara District
  Kitakanbara District, Niigata
  is a district located in Niigata, Japan. As of April 1, 2005, the district has an estimated population of 13,528. The total area is 37.99 km². The district has one town: Seirō.- History :...
  
  ) merged to form the city of Tainai
  Tainai, Niigata
  is a city located in Niigata Prefecture, Japan.As of April 1, 2005, it has an area of 265.18 km² and a population of 33,309.-History:The city was established on September 1, 2005 as a result of the merger between the town of Nakajō and the village of Kurokawa, both from Kitakanbara District...
  
  .

• On October 1, 2005 - The town of Shiozawa
  Shiozawa, Niigata
  Shiozawa was a town located in Minamiuonuma District, Niigata, Japan.As of 2003, the town had an estimated population of 20,142 and a density of 105.94 persons per km². The total area was 190.12 km²....
  
   from Minamiuonuma District
  Minamiuonuma District, Niigata
  is a district located in Niigata, Japan.As of 2003, the district has an estimated population of 72,908 and a density of 77.41 persons per km². The total area is 941.82 km².- Mergers :...
  
   merged into the city of Minamiuonuma
  Minamiuonuma, Niigata
  is a city located in Niigata Prefecture, Japan. It has an area of 584.82 km² and a population of 62,733 .-History:*The city was established on November 1, 2004 in a merger of the towns Muikamachi and Yamato, both from Minami-Uonuma District, Niigata.*On October 1, 2005, the town of Shiozawa...
  
  .

• On October 10, 2005 - The town of Maki from Nishikanbara District
  Nishikanbara District, Niigata
  is a district located in Niigata, Japan.As of March 20, 2006, the district has an estimated population of 8,537. The total area is 25.22 km².- Towns and villages :On March 20, 2006, the towns of Bunsui and Yoshida merged with the former city of Tsubame...
  
   merged into the city of Niigata
  Niigata, Niigata
  is the capital and the most populous city of Niigata Prefecture, Japan. It lies on the northwest coast of Honshu, the largest island of Japan, and faces the Sea of Japan and Sado Island....
  
  .

• On January 1, 2006 - The old city of Gosen
  Gosen, Niigata
  is a city located in Niigata, Japan.As of 2005, the city has an estimated population of 56,965 and a density of 382.89 persons per km². The total area is 351.87 km².The city was founded on November 3, 1954...
  
   merged with the town of Muramatsu
  Muramatsu, Niigata
  Muramatsu was a town located in Nakakanbara District, Niigata, Japan.As of 2003, the town had an estimated population of 20,066 and a density of 79.29 persons per km². The total area was 253.07 km²....
  
   from Nakakanbara District
  Nakakanbara District, Niigata
  Nakakanbara was a district located in Niigata Prefecture, Japan.-History:In 1878, Nakakanbara District was established.The district started to shrink after the town of Nuttary merged and Niigata continued to absorb the district...
  
   (dissolved by this merger) to form the new city of Gosen
  Gosen, Niigata
  is a city located in Niigata, Japan.As of 2005, the city has an estimated population of 56,965 and a density of 382.89 persons per km². The total area is 351.87 km².The city was founded on November 3, 1954...
  
  .

• On January 1, 2006 - The city of Tochio
  Tochio, Niigata
  was a city located in Niigata Prefecture, Japan. The city was founded on June 1, 1954.As of 2003, the city had an estimated population of 23,855 and the density of 116.41 persons per km²...
  
  , the towns of Teradomari
  Teradomari, Niigata
  was a town located in Santō District, Niigata, Japan.As of 2003, the town had an estimated population of 11,766 and a density of 202.30 persons per km². The total area was 58.16 km²....
  
   and Yoita
  Yoita, Niigata
  was a town located in Santō District, Niigata, Japan.As of 2003, the town had an estimated population of 7,380 and a density of 368.08 persons per km². The total area was 20.05 km²....
  
   and the village of Washima
  Washima, Niigata
  Washima was a village located in Santō District, Niigata, Japan.As of 2003, the village had an estimated population of 4,814 and a density of 151.10 persons per km². The total area was 31.86 km²....
  
   from Santō District
  Santo District, Niigata
  is a district located in Niigata, Japan.- History :* Before the Edo Period, Santō District was part of the now-defunct Koshi District.* On April 1, 2005 the towns of Koshiji and Mishima merged into the city of Nagaoka....
  
   were all absorbed into the city of Nagaoka
  Nagaoka, Niigata
  is a city located in the central part of Niigata Prefecture, Japan. It is the second largest city in the prefecture, behind the capital city of Niigata...
  
  .

• On March 20, 2006 - The old city of Tsubame
  Tsubame, Niigata
  is a city located in Niigata, Japan.The city was founded on March 31, 1954 by merging with 4 towns and villages. Nearly 52 years later on March 20, 2006, the old Tsubame merged with Bunsui and Yoshida from Nishikanbara District to form the new city of Tsubame....
  
   merged with the towns of Bunsui
  Bunsui, Niigata
  was a town located in Nishikanbara District, Niigata, Japan.As of April 1, 2005, the town had an estimated population of 15,130. The total area was 39.61 km²....
  
   and Yoshida
  Yoshida, Niigata
  was a town located in Nishikanbara District, Niigata, Japan. Yoshida is now a part of Tsubame.As of April 1, 2005, the town had an estimated population of 24,937. The total area was 32.00 km²....
  
   from Nishikanbara District
  Nishikanbara District, Niigata
  is a district located in Niigata, Japan.As of March 20, 2006, the district has an estimated population of 8,537. The total area is 25.22 km².- Towns and villages :On March 20, 2006, the towns of Bunsui and Yoshida merged with the former city of Tsubame...
  
   to create the new city of Tsubame
  Tsubame, Niigata
  is a city located in Niigata, Japan.The city was founded on March 31, 1954 by merging with 4 towns and villages. Nearly 52 years later on March 20, 2006, the old Tsubame merged with Bunsui and Yoshida from Nishikanbara District to form the new city of Tsubame....
  
  .

• On April 1, 2008 - The old city of Murakami
  Murakami, Niigata
  is a city located in northern Niigata, Japan.On April 1, 2008, the city merged with the towns of Sanpoku and Arakawa, and the villages of Asahi and Kamihayashi, all from Iwafune District....
  
   merged with the towns of Sanpoku
  Sanpoku, Niigata
  was a town located in Iwafune District, Niigata, Japan.On April 1, 2008 Sanpoku, along with the town of Arakawa, and the villages of Asahi and Kamihayashi, all from Iwafune District, was merged into the city of Murakami....
  
   and Arakawa
  Arakawa, Niigata
  was a town located in Iwafune District, Niigata, Japan.On April 1, 2008 Arakawa, along with the town of Sanpoku, and the villages of Asahi and Kamihayashi, all from Iwafune District, was merged into the city of Murakami....
  
   and the village of Asahi
  Asahi, Niigata
  was a village located in Iwafune District, Niigata, Japan.The village was named after the Asahi Mountains.As of 2005, the village had an estimated population of 11,836 and a density of 18.69 persons per km²...
  
   and Kamihayashi
  Kamihayashi, Niigata
  was a village located in Iwafune District, Niigata, Japan.As of 2003, the village had an estimated population of 10,228 and a density of 124.46 persons per km²...
  
   from Iwafune District
  Iwafune District, Niigata
  is a district located in Niigata, Japan.As of May 1, 2008, the district has an estimated population of 7,137. The total area is 309.47 km².The district currently has two villages.* Awashimaura* Sekikawa...
  
   to create the new city of Murakami
  Murakami, Niigata
  is a city located in northern Niigata, Japan.On April 1, 2008, the city merged with the towns of Sanpoku and Arakawa, and the villages of Asahi and Kamihayashi, all from Iwafune District....
  
  .

• On March 31, 2010 - The town of Kawaguchi
  Kawaguchi, Niigata
  was a town located in Kitauonuma District, Niigata, Japan.As of 2003, the town had an estimated population of 5,549 and a density of 110.91 persons per km². The total area was 50.03 km².On March 31, 2010, Kawaguchi became a part of Nagaoka city....
  
   was absorbed into the city of Nagaoka
  Nagaoka, Niigata
  is a city located in the central part of Niigata Prefecture, Japan. It is the second largest city in the prefecture, behind the capital city of Niigata...
  
  . Kitauonuma District
  Kitauonuma District, Niigata
  was a district located in Niigata, Japan.- History :* On 1954, areas now covering Ojiya merged and gained city status.* On November 1, 2004 towns of Horinouchi and Koide, and the villages of Hirokami, Irihirose, Sumon and Yunotani merged to create the new city of Uonuma; leaving the village of...
  
  was thereby dissolved.