Objective To investigate prevalence of resistance genes for β-lactams in clinically isolated multidrug-resistant Acinetobacter baumannii (MDRAB)in a hospital.Methods 22 clinically isolated MDRAB strains were performed antimicrobial susceptibility testing,resistance genes forβ-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. Results The 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/sul-bactam 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.Conclusion Carriage of IMP ,TEM,PER,and OXA-23 resistance genes are the major resistance mechanisms of MDRAB to β-lactamase antimicrobial agents in this hospital.