Abstract: Objective To explore pesticide resistance of houseflies and its countermeasures in mining areas of Shengli petroleum field.Methods Houseflies were collected with fly-trap method and pesticide resistance of their fist or second generations raised in the laboratory were tested with topical application method.Pesticide resistance-related proteins and enzyme activities in the houseflies were determined simultaneously.Results High-resistance of the houseflies to deltamethrin,beta-cypermethrin,and permethrin was observed,with the resistance coefficients(R/S)of 22.86,24.12,and 19.37,respectively,and a declined trend for the resistance to dichlorvos.After selection breeding for resistance to beta-cypermethrin,the activities of acetyl cholinesterase,catalase,and glutathione S-transferase of the houseflies were increased markedly to 9.012,10.012,and 421.35 U/mgprot.The resistance to beta-cypermethrin of the housefly populations showed a natural decline without selection pressure.Conclusion Comprehensive measures for housefly control,reasonable application of pesticides,and regular pesticide resistance monitoring should be adopted to restrain pesticide resistance of houseflies in oil mining areas.