Jiandao

Jiandao, also known in Korean as Gando, refers to a small piece of marsh land between the Yanbian Korean Autonomous Prefecture and Helong in Jilin, Northeast China. The original Chinese name of Jiandao is Jiajiang(Chinese: 假江; pinyin: Jiájiāng).

Another way to define Jiandao was provided by the Imperial Japan in early 20th century. An expanding Japanese empire claimed that Jiandao included territory of four counties (Yanji, Wangqing, Helong and Hunchun) of Jilin province and ethnic Koreans living in this region should be placed under its influence, which would give Japan a chance to impose colonial jurisdiction on the region. As one of its first set of attempts to annex northeast China and conquer other parts of mainland China, Imperial Japanese forces in Korea invaded Jiandao in 1907. But Imperial Japan withdrew its invading troops back to Korea in 1909 and recognized the border that was present along Tumen River before the invasion, under the diplomatic pressure from China.

Most of the region defined by Japan in early 20th century as Jiandao is part of Yanbian Korean Autonomous Prefecture, a part of Jilin Province in the northeast of the People's Republic of China (PRC). The area of the prefecture is approximately 42,000 square kilometers in size and home to about 810,000 ethnic Koreans.

In China, Yanbian is the name used, and Jiandao is not used, due to its association with Japanese colonial occupation. North Korea and South Korea recognize the region as a part of the People's Republic of China, but there are some nationalist elements in South Korea that endorse the idea that the region should be a part of modern-day Korea. These groups claim what happened in Jiandao between 1907-1909 (Japan's invasion and subsequent withdrawal) was an "illegal transfer" of "Korean territory" between Japan and China.