Ulansuhai Nur or Wuliangsuhai (Chinese: 乌梁素海; pinyin: Wūliángsù Hǎi) is a freshwater lake in located in southwest Inner Mongolia, North China, on the north (left) bank of Yellow River's Ordos Loop. The lake has an area of 233 km (90 sq mi), a north–south length of 35.4 km (22.0 mi) and mean east–west width of 6.6 km (4.1 mi) (max 12.7 km or 7.9 mi), with a drainage area of 11,800 km (4,600 sq mi) at an elevation of 1,018.79 m (3,342.5 ft).

Ulansuhai Nur is a rare big multi-functional lake in the desolate and drought-stricken grassland. It has 150 km (58 sq mi) of bulrush square kilometers with nearly 200 species of birds and over 20 species of fish.