Abstract: OBJECTIVE To investigate the homology and the prevalence of β-lactamase genes in multidrug-resistant Acinetobacter baumannii（MDRAB）isolated in hospital,so as to provide the basis for the control of nosocomial infections.METHODS A total of 9strains of MDRAB were isolated from Nov.2013 to Dec.2013.Identification and susceptibility tests of bacteria were performed by VITEK2 automated microbial analyzer,and partial antimicrobial drug susceptibility tests were conducted by the disk diffusion method.Homology analysis was performed by pulsed field gel electrophoresis（PFGE）,polymerase chain reaction（PCR）was used to detect resistance genes for β-Lactamases,and portion of positive genes were sequenced.RESULTS There were 2types of PFGE profiles in 9strains of MDRAB,including 8strains of type A strain（8/9）and 1strain of type B（1/9）.All of these stains carried OXA-51 gene and OXA64 group genes,and OXA-23 qc gene was identified in 8strains（8/9）,TEM gene was identified in 3strains（3/9）.There were 5（5/9）strains of specimens isolated in ICU,while 3（3/9）strains in neurosurgery ward.CONCLUSION MDRAB strains with the same PFGE profile and the sameβ-lactam resistance genes were existed in this hospital during this time.Hospitals should focus on the disinfection and isolation in ICU and neurosurgery ward.