Abstract: We have tested the poisonous power to Pantana phyllostachysae of three different kinds of Beauveria bassiana,Bacillus thuringensis and 80% DDVP,against 2～3 instars larvae.The results showed,the sequence of poisonous power is Bb Dendrolimus (made in Yongan)>Bt>Bb P.phyllostachysae (Shaowu).Bised on the biological measure in laboratory and experment in field,the sptimum composition of compound micribial insecticides of P.phyllostachysae is chose,which are Bb Dendrolimus 1.2×10 8 spore/mL+Bt 1.2×10 8 spore/mL+80% DDVP 1/30 000 against 2～3rd instars larvae and Bt 6×10 8 spore/mL+Bb P.phyllostachysae 1.2×10 8 spore/mL+80% DDVP 1/5 000 to 4～6th instars larvae.