Abstract: Effects of six pesticides commonly used in tea plantations on the spore germination and hyphae growth of Beauveria bassiana were studied.The results showed that the two chemical insecticides(imidacloprid and Bifenthrin) have the best inhibitory effects on the development of B.bassiana,and followed by the two fungicides(carbendazim and mancozeb) and the two botanical insecticides(qingyuanbao and veratrine) used at commonly concentration.However,Bifenthrin had no siginficant negative impact on the development of B.bassiana.However,compatibility of B.bassiana with insecticides with one tenth of the commonly used concentration was good,except for veratrine.