Objective:To investigate the homology and prevalent cases of multidrug-resistant Acinetobacter baumannii (MDRAB) so as to provide reference for the prevention of nosocomial infection and clinical reasonable application of antibiotics. Methods:A total of 31 MDRAB isolates between June 2012 and December 2012 were collected,the susceptibility test of 12 antimicrobial agents was determined by K-B method,and the homology analysis of the strains was determined by pulsed-field gel electrophoresis(PFGE). Retrospective analysis of MDRAB sample cases was performed. Results:The antimicrobial susceptibility showed that the resistance rate of 31 MDRAB isolates to 9 antibiotics was 100%,including 4 kinds of antibacterial drugs. The results of PFGE demonstrated that 31 isolates were classified into 5 distinct genotypes,among those 20 isolates (accounting for 64.52%) of clone B were the predominant epidemic strains. The patients with MDRAB infection were distributed among 8 wards and mainly centralized in the intensive care unit,cardiothoracic surgery and geriatric intensive care unit. The average age of the patients was 64 years,and 97% of them had undergone invasive procedures. Conclusion:The MDRAB was seriously resistant to almost all clinically-used antibiotics. It may be closely related to a variety of factors,such as clonal spread,old age of patients,invasive treatment and patients with multiple underlying medical conditions.