Abstract: In order to get better understanding of the ant diversity of tropical forest ecosystem in western Yunnan, the ant diversity in Tongbiguan Natural Reserve and adjacent area is measured through sample-plot method.The results show that 130 species belonging to 49 genera and 10 subfamilies are recorded.Main indices of ant communities from 22 sample plots are as follow, species number 0-39(average 17.6), individual density 0.0-525.2 heads/m²(average 109.2 heads/m²), diversity index 0.000 0-2.629 2(average 1.535 5), evenness index 0.362 7-0.772 3(average 0.544 6), dominant index 0.101 8-1.000 0(average 0.322 6).Similarity coefficients between ant communities are 0.000 0-0.307 7, which represent extremely dissimilar to moderately dissimilar level.We conclude that main indices of ant communities express multi-domain effect phenomena on the base-domain effect background, which indicates that there are assemblages of north tropical, south subtropical and middle subtropical ant species distributes on the vertical band of the mountain.These assemblages of ant species have different conservation value.Ant species richness and diversity are commonly influenced by latitude and altitude.There are more ant species lives in the low latitude and altitude area, as the latitude and altitude increasing, ant species richness and diversity decrease.Ant communities on the middle and low section of the mountains at Tongbiguan Nature Reserve and adjacent area are commonly deeply disturbed by human activity, which need pay sufficient attention in conservation.