How long is the Lancang River (Mekong River)?

Lancang River is the name of the upper Mekong River in China. It is one of the longest rivers in southwest China, the ninth longest river in the world, the fourth longest river in Asia and the first river in Southeast Asia. Zhaqu at the source of Lancang River originated in Jifushan, Zaduo County, Yushu Tibetan Autonomous Prefecture, Qinghai Province, with an altitude of 5,200 meters and a total length of 2 1.39 kilometers. Lancang River flows through Qinghai, Tibet and Yunnan provinces, and leaves Mengla County, Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, and becomes the boundary river between Laos and Myanmar before it is called Mekong River. Mekong River flows through Laos, Myanmar, Thailand, Cambodia and Vietnam, and flows into the South China Sea of China in Ho Chi Minh City, Vietnam.