Abstract: Ant community and species diversity from west slope of Nushan Mountain in northwestern Yunnan Province were probed by sample plot investigation method. The area is relatively rich in ant fauna in China. It is obviously rich in subfamilies and genera. The richness of species diversity is decreased along with the increment of altitude and from south to north. Species richness, individual density and Shannon-Wiener index are mainly restricted by temperature accumulation of microhabitats and forest structure. The microhabitat with good forest structure and higher temperature accumulation had higher species richness and Shannon-Wiener index. An open habitat with higher temperature accumulation possesses higher individual density. Shannon-Wiener index, Pielou evenness index and Simpson predominant index of the ant communities could well reflect the west slope of Nushan Mountain which was significantly rich in habitat diversity, the middle and lower portions of the slope were deeply disturbed by mankind.