Objective To investigate the distribution of Aedes aegypti in border area in Yunnan province, providing scientific information for dengue control. Methods The distribution of Ae. aegypti was investigated by collecting mosquito larvae in different breeding sites and identifying fourth instar larvae; Aedes mosquito larva population density was investigated by Aedes Breteau index and container index. Results Total of 159 924 containers were investigated from 17 border counties, of those 2388 containers were positive; the Breteau index was 3.97, the container index was 1.46. There were 7489 individual larvae were collected, belonging to 3 species, of those 3303 individual larvae were Ae. aegypti, accounting for 44.10% of total collected larvae, 4119 individual larvae were Ae. albopictus, accounting for 55.00% of total collected larvae,12 individual larvae were Ae. annandalei, accounting for 0.90% of total collected larvae. Aedes mosquito larva population density peaks were occurred from May to October, its highest peaks were July and August. Ae. aegypti distributed in 7 counties i.e. Jinghong, Mengla, Menghai, Yingjiang, Longchuan, Ruili and Lushui. Conclusion Aedes aegypti distributed in 7 border counties of Yunnan province, and results suggested that its distribution was expanding to the neighbor areas, which warrants high attentions by disease control department.