Abstract: Anopheles sinensis adults were captured from Huaibin County and raised in laboratory. Larvae dipping method and the WHO tubes were used to determine the resistance of F1 Ⅳ-stage larvae and 3-5 day-old adult mosquitoes to dimethyl dichloroviny phosphate（DDVP）, deltamethrin, and arprocarb. The activity of acetylcholine esterase（AChE） of larvae and adult mosquitoes was measured by colorimetric method before and after the respective addition of the 3 insecticides. The results showed that the mortality of adult mosquitoes in 0.05% deltamethrin testing tube （0.017 8 g/m2） was 51.2%, which was less than 80% and judged as resistant group. The LC₅₀ of larvae to DDVP, deltamethrin, and arprocarb were 2.76, 320.85, 754.32 mg/L, respectively. The inhibition rates of 0.005 mmol/L DDVP, deltamethrin, and arprocarb to AChE activity were 77.8%, 62.8%, and 58.9% in larvae, while 76.1%, 62.2%, and 58.22% in adults, respectively, showing a significant inhibition on the AChE activity of An. sinensis （P<0.01）.

Key words: Anopheles sinensis, Resistance, DDVP, Deltamethrin, Arprocarb, Acetylcholine esterase