To screen the identifier of B.thuringiensis, genomic DNA of B.thuringiensis, B.cereus and control strains were amplificated by ERIC-PCR. Fragments amplified from B.thuringiensis were retrieved, cloned，marked by α-³²P, dot blot and southern hybridized with genomic DNA of these strains. It shows that every strains of B. thuringiensis can be amplified to produce a 250bp fragment, and both B.thuringiensis and B.cereus can be amplified to produce a 600bp fragment. Hybridization result between 569bp probe and genomic DNA of B.thuringiensis shows a high specificity. Discrimination and genetic relationship between B.thuringiensis and B.cereus can be revealed by ERIC fingerprint. This research indicates that ERIC-PCR technique is a practical method in the detection and characterization of B.thuringiensis and B.cereus.