Abstract: Objective To study the genotype of strains producing ESBLs among Escherichia coil and Klebsieua pneumoniae to provide references for the clinical application of　drugs. Methods PCR was used to determine the genotype of the ESBLs .Results The percentage of TEM type, SHV type and NO-TEM-NO-SHV type in Escheroichia coil was 80.4%, 7.8% and 11.8%，in Klebsieua pneumoniae was 78.1%, 71.9% and 25.0%. Most of Klebsieua pneumoniae produced more than two Extended Spectrum β-lactamases 。Conclusions the differences in genotype has the regional characteristics.