【Abstract】 Objective To observe the sensitivity of Anopheles sinensis to deltamethrin and cyfluthrin in malaria epidemic areas of Jiangsu province. Methods The adult mosquito test kit was used in this study recommended by WHO. The quantity of adult mosquitoes knocked down by deltamethrin and cyfluthrin was counted after exposure 10 min, 15 min, 20 min, 30 min, 40 min, 50 min and 60 min, and its mortality after treatment for 24 h was recorded. Results The knock down rates of An.sinensis to deltamethrin in Xuyi, Sihong, Suining, and Yixing county (city) were 67.37%, 64.00%, 71.43%, and 78.40% at 60 min after treatment, respectively, and the mortalities at 24 h after treatment were 68.42%, 68.00%, 72.53% and 76.80%, respectively. The resistance  level  of  the  An.sinensis  to  deltamethrin  in  four  areas  investigated  was  evaluated as “R”.  The knock down rate of An.sinensis to cyfluthrin were 84.13%, 91.76%, 89.80% and 100% at 60 min after treatment in Xuyi, Sihong, Suining, and Yixing county(city), respectively. The mortalities at 24 h after treatment were 85.71%, 91.76%, 93.88% and 100%, respectively. The resistance level of An.sinensis to cyfluthrin in Yixing area was assessed as “S”, and “M” level in other three counties. Conclusion An.sinensis has high resistance to deltamethrin and low resistance to cyfluthrin in parts of malaria epidemic areas. In order to prevent development of resistance, the integrated management measures should be taken in the future.