Abstract: In order to reveal ant diversity regularity in mountainous area of Southwestern China, ant species diversity of western Daliangshan, Sichuan Province was surveyed through sample-plot method. The findings indicated that the area with vertical altitude range 2 711 m has rich ant species, totally 95 species belonging to 37 genera and 8 subfamilies of Formicidae are recognized. Two dominant species (Pheidole nietneri Emery and Paraparatrechina sakurae Ito, occupying 2.10%) are found in the ant community, meanwhile 4 common species (occupying 4.21%), 17 relative-common species (occupying 17.89%), 34 relative-rare species (occupying 35.79%) and 38 rare species (occupying 40.00%) are observed in the community. In conclusion, ant species numbers, individual densities and diversity indexes are generally decreasing with altitude rising, it means that altitude and air temperature are the key factors restricting main indexes of ant communities. Meanwhile, the main indexes of ant communities commonly express multi-domain effect phenomenon, it is due to climatic elements and human disturbance. In the north part of the area, the multi-domain effect phenomenon is mainly influenced by climatic elements, but the phenomenon is mainly influenced by human disturbance in the south part of the area. Although the 8 vertical zones of western Dliangshan have been disturbed by human beings in varying degrees, large area natural forests are retained in the north part like Muli County and middle part like Yanbian County, in addition to the mountainous and relatively lower altitude characters, the ant fauna and diversity of the area is rank at a relatively higher level in Sichuan Province. Ant communities from various vertical zones are significantly diverse, and have distinct ecological function and protective value.