Abstract: Objective To investigate the resistance of mosquito against insecticides in Songjiang,providing scientific basis for appropriate application of insecticides. Methods The dipping method and drug velum contacting method were used for determination of the resistance of culex pipiens pallens and anopheles hurcanus sinensis against insecticides. Results Culex pipiens pallens were found to have high resistance to DDVP, resistance coefficient 30.07, and low resistance to cypermethrin, fenobucarb and deltamethrin, resistance coefficient 3.96, 3.25 and 2.79, while their sensitivity to beta-cypermethrin, resistance coefficient 0.28. Anopheles sinensis had R level resistance to DDT and deltamethrin, mortality rates 73.36% and 57.50% respectively. Conclusion Mosquitos in Songjiang District have developed different degrees of resistance to insecticides. In order to control and delay their resistance, insecticides should be alternated and combined in application.