Objective Master the mosquito species composition, density and seasonal fluctuation before the second Beijing Capital Airport construction, to provide a scientific reference for the control of mosquito-borne infectious diseases. Methods Based on Daxing covers location of airport construction plan, selecting six natural villages for monitoring from east to south-west. Opening the lure mosquito lamp at one hour before sunset, continuous monitor mosquito for 2 hours using the lure mosquito lamp of carbon dioxide, once every ten-day in June to October 2014. Identifying species and counting the captured mosquitoes. Results In total 5883 mosquitoes were captured, belonging to two subfamilies, four genera, five species. Armigeres subalbatus was collected in Daxing area for the first time. Culex pipiens pallens was the perdominant species. The mosquitoes density peak was in late June. Testing negative results of Japanese encephalitis virus nucleic acid. Conclusion Mastering the mosquito species composition, density and seasonal fluctuation before the second Beijing Capital Airport construction. The monitoring results can provide a scientific basis for the assessment of risk correlation mosquito-borne infectious diseases, and for the prevention and control of mosquitoes.