Namwan River (; ) is a river in China and Myanmar. Namwan River rises in the mountain called Ganya Liangzi at the northern section of Longchuan County, Yunnan. It through the Longchuan county, as the major irrigation water source of the fields in the basin. And entering the valley at the southwest of Zhangfeng, the county town of Longchuan. Then it became the boundary between Myanmar and China until entering Shweli River at Nongdao, Ruili.