Salween River much of its length, the Salween's course is nearly parallel to that of the much larger Mekong in the east. Although the commonly accepted name is Salween, the river is known by a handful of other names regionally: "Nu" in China, "Thanlwin" in southern Burma, and "Salawin" on the border of Thailand and Burma. Several major sub-continental drainage basins border on the Salween. The Mekong basin forms nearly the entire eastern boundary of the watershed, while the Irrawaddy River flows southwards on the west side of the basin. The smallest boundary is formed by the Yangtze to the extreme north.
River systems of Thailand Mekong River Commission. The extreme seasonal variations in flow and the presence of rapids and waterfalls have made navigation extremely difficult. Approximately half the river's length is in China, where it is known as the "Lancang Jiang" (澜沧江 Láncāng Jiāng) or "Meigong" in Chinese (). The river forms the border between Myanmar and Laos for , at the end of which it meets the tributary Ruak River at the Golden Triangle. This point also marks the division between the "Upper" and "Lower Mekong". The river then divides Laos and Thailand, before a stretch passing through Laos alone. It is known