【Abstract】 Objective To compare the characteristics of mosquito communities structure at different altitude of Mengshan mountains Methods The mosquito communities structure at different altitude of Mengshan mountains were compared and analyzed with the indexes of substance content of biota（SCB）, species abundance and diversity（SAD）, probability of interspecific encounter（PIE）, community uniformiry（CU）, biomass （BM） and species density（SD）, and the relativity of mosquito communities comparability index was performed. Results A total of 2013 mosquitoes were colleted. Of which, a sum of 1724 mosquitoes were collected within 200-300 m, accounting for 85%. There were 257 mosquitoes at 700-800 m, accounting for 13%, and only 32 mosquitoes at 1156 m which was the top of the mountain, accounting for 2%. The six index mentioned above were 13, 0.345, 0.272, 0.310, 1.20, and 1724 at 200-300 m, 12, 0.417, 0.443, 0.417, 0.18, and 257 at 700-800 m, and 9, 0.677, 0.845, 0.750, 0.06 and 32 at 1156 m. The comparability index between 700-800 m and 1156 m was higher with the value of 0.3625, following with the indexes between 700-800 m and 200-300 m which the values were all 0.1852. And it was the lowest between 1156 m and 200-300 m with the value of 0.1452. The results showed that the distance was nearer, the comparability was bigger, according with the practical investigation results. Conclusion There was distinct difference among the mosquitoes communities diversity at the different altitude. The SCB, BM and SD of mosquito communities in higher altitude were lower than those in lower altitude. But the CU, SAD and PIE of mosquito communities in higher altitude were higher than those in lower altitude. Furthermore, the distance of habitats was nearer, the community structures were more similar, and vice versa. The biological diversity was of great importance to study community structure of mosquitoes.