Abstract: Six commonly used pesticides were sprayed at sublethal concentrations (LC_0-13) on common .bean (Phaseolus vulgaris) leaves in the laboratory to test their effect on the predacious mite. The results showed that the pesticides were baneful to the reproduction of P. persimilis. Applications of dicofol at 84 ppm, omethoate at 1 ppm, fenvalerate at 0.2 ppm, cypermethrin at 0.1 ppm, deltamethrin at 0.025 ppm and meothrin at 0.026 ppm resulted in a fecundity reduction of 35.3%, 41.2%, 20.8%, 15.1%, 47.4% and 74.7% of the predator, respectively, comparing to those in the control treatment. Treatment of bean plant with these pesticides at the sublethal concentrations in the greenhouse further demonstrated harmful effects on the settlement of P. persimilis. The settlement rate of the predator on the plants treated with the forenamed six pesticides at the above concentrations was 48.4%, 50.0%, 25.0%, 11.7%. 3.3%. and 6.7%, respectively, while that in the control was 96.7%. The detrimental impact of the pyrethroids on the settlement of P. persimilis was significantly greater than that of omethoate and dicofol.