The genes ( cry I, III, IV genes) encoding crystal protein body (CPB) producing Bacillus thuringiensis were analyzed by polymerase chain reaction (PCR) with synthetic oligonucleotide primers (Lep1A, Lep1B, Co12A, Co12B, Dip1 A and Dip1B). These primer pairs could amplify the 490, 797, 1060-bp region in cry genes. All CPB-producing B. thuringiensis strains tested yield an amplified DNA fragment, while non-CPB producing B. thuringiensis and B. cereus strains did not. The PCR provides a rapid and simple means to detect CPB-producing B. thuringiensis .