The effect of 6 common chemical insecticides on the vitality of Beauveria bassiana and B.tenella conidia was studied.The results showed that the inhibition of 6 chemical insecticides on the Beauveria bassiana and B.tenella conidia was different.The insecticides in the different dosage had a greater difference on the inhibition to conidial vitality.In the lethal dosage,the insecticides inhibited more conidia vitality of B.tenella than that of B.bassiana.In sublethal dosage,most of the insecticides had no inhibition on the conidial vitality.