The Salween River originates in the eastern highlands of the Tibetan Plateau and flows through valleys that are at first steep and narrow, then increasingly broad as the river approaches the tropical lowlands. Eventually it enters the Andaman Sea in eastern Myanmar.

The 2815 km long Salween river runs parallel to the mighty Mekong River for much of its course and forms part of the border between Myanmar and Thailand. When it flows through Yunnan, it is known as the Nujiang river.