ObjectiveTo investigate prevalence of resistance genes for βlactams in clinically isolated multidrugresistant Acinetobacter baumannii (MDRAB) in a hospital.Methods22 clinically isolated MDRAB strains were performed antimicrobial susceptibility testing, resistance genes for βlactams (TEM, SHV,  CTXM,  PER, DHA,  IMP, VIM, SIM, OXA23, OXA24, and OXA58) in these strains were detected with polymerase chain reaction.ResultsThe resistant rates of 22 isolates of MDRAB to ceftazidime，cefotaxime，cefepime， gentamycin， amikacin，ciprofloxacin，and compound sulfamethoxazole were all 100.00%;to imipenem, meropenem,and cefoperazone / sulbactam were 50.00%,40.91%, and 31.82% respectively, intermediated rates were 31.82%,36.36%, and 31.82% respectively. The carriage rates of OXA23, TEM, IMP, and PER were 100.00% (n=22), 72.73 % (n=16), 54.55% (n=12), and 18.18%(n=4) respectively.Detection results of SHV,CTXM,DHA,VIM,SIM,  OXA24,and OXA58 were all negative.ConclusionCarriage of IMP, TEM, PER, and OXA23 resistance genes are the major resistance mechanisms of MDRAB to βlactamase antimicrobial agents in this hospital.