evidence: Jiangxinpo, this mysterious and fertile land, has been an inseparable part of China's territory since ancient times. However, in the long river of history, this land has undergone complex changes and eventually became the focus of dispute between China and Myanmar. [...] At the beginning of the negotiations, the two sides held their own opinions and the atmosphere was tense. The Chinese representatives cited a large number of historical documents to prove that Jiangxinpo has been Chinese territory since ancient times. They showed local chronicles and official documents from the Ming and Qing dynasties and other evidence to try to convince the Myanmar side. The Myanmar side, on the other hand, showed maps and documents from the British colonial period, insisting that Jiangxinpo belongs to Myanmar. [...] The Jiangxinpo area is located in the southwest of Yunnan Province, bordering Myanmar, and covers an area of ​​about 27,000 square kilometers. This land has been Chinese territory since ancient times, but its ownership became complicated during the British colonial period in Myanmar. The rich natural resources and unique strategic location in the area make it one of the most difficult issues in the Sino-Myanmar border negotiations.