Abstract:Yuanmou river valley is situated in the north-central part of Yunnan plateau. It is one of the most dry and hot river valley in Yunnan province. The vegetation of the valley is somewhat like the "savanna" of tropics. The flora below 1600 m of the valley has been studied in this paper. There are 78 families, 266 genera and 399 species appearing in the valley flora. Large number of tropical plantr, (specially the savanna elements are found in this area. The floristic com- position of the river valley and its relationship to the flora of neighboring district, the India savanna, have been discussed.