The Yalu River forms the border between China and North Korea for most of its length.
Known as the Amnok River in Korean, the Yalu rises on Mount Paektu, a volcanic mountain on the China–North Korea frontier. It flows generally southwest for about 790 kilometres before reaching Korea Bay. Much of its course separates China’s Liaoning and Jilin provinces from North Korea, making it one of East Asia’s important political and geographic boundaries.
The border is not formed by the Yalu alone. Near the eastern end of the frontier, the Tumen River also separates North Korea from China, and in places the boundary follows watersheds or land features. That is why the wording “for most of its length” matters: the Yalu is the principal border river, but it does not define the entire boundary.
The river has major historical significance. During the Korean War, the Yalu marked the area near China’s border, and the bridges at Dandong and Sinuiju became strategically important. The most famous is the Sino-Korean Friendship Bridge, which still links the two countries. The Yellow River and Mekong are unrelated rivers and do not form this border.