Objective In order to master the species density, distribution and seasonal variation of Aedes albopictus which spread dengue fever in Sichuan province, provide a scientific, normative and reasonable guide to Ae. albopictus control in Sichuan province, and provide a basic data for dengue outbreak risk predict and early warning, assess the prevention and control effect, draw up a prevention and control plan and so on. Methods Larval breeding was evaluated using the Breteau index(BI), and adult mosquitoes were evaluated by double-mosquito net trapping method. Results The Ae. albopictus BI for an average level was 11.96, the BI in residential area was 17.37, and the park/green belt was 7.76; the mosquito-curtain trap index for an average of 4.14/net·hour, the mosquito-net trapping index in residential area was 6.27/net·hour, and the park/greenbelt was 3.70/net·hour. Conclusion The density of Ae. albopictus was high in Sichuan province. Once there is an imported case of dengue fever, there will be a risk of dengue transmission even outbreak.