目的 了解杭州市家蝇乙酰胆碱酯酶（AChE）活性，分析其与残杀威高抗的相关性。方法 采用点滴法测定家蝇对残杀威的抗药性表型，利用比色法测定家蝇现场种群与敏感品系的AChE水解活性及家蝇现场种群的残存活性。结果 家蝇现场种群的半数致死量（LD₅₀）> 400 μg/只，抗性倍数> 2 500倍；家蝇敏感品系和现场种群的AChE水解活性分别为（0.291±0.114）和（0.360±0.104）μmol/（mg·min），差异有统计学意义（t=2.692，P=0.009）；现场种群对残杀威的不敏感个体在种群中的比例为38.89%。结论 杭州市家蝇现场种群AChE的生化特性较敏感品系发生了较大改变，AChE水解活性升高，对残杀威的敏感度降低，提示其可能是导致杭州市家蝇现场种群对残杀威产生高抗的主要原因。

Objective To measure the acetylcholinesterase (AChE) activity of Musca domestica in Hangzhou city, finding its correlation with the high resistance to propoxur. Methods Determiningpropoxur resistance level of M. domestica with topical application method, using colorimetric method to calculate the hydrolysis activity of susceptible strains and field strains, analyzing the residual activity of field strains. Results The LD₅₀ of field strains was higher than 400 μg, and the resistance coefficient was higher than 2 500. The AChE hydrolysis activity of susceptible strains and field strains were (0.291±0.114) and (0.360±0.104) μmol/(mg·min), respectively (t=2.692, P=0.009). The field strains in the proportion of 38.89% were insusceptible to propoxur. Conclusion The biochemical properties of AChE in Hangzhou city field strains were greatly changed as compared with the susceptible strains, the AChE hydrolysis activity increased and its susceptibility to propoxur declined, suggesting those may be the main causes of the high propoxurresistance of M. domestica in Hangzhou city.