Abstract: Objective: To study the characteristics of antibiotic susceptibility of Acinetobacter baumannii so as to provide basis for clinical application.Methods: The distribution of One hundred thirty-five stains Acinetobacter baumannii isolated from clinic and their drug resistance were analyzed retrospectively.Results: The incidence of Acinetobacter baumannii was the highest in the intensive care units(48.1%),and the department of orthopaedics(14.8%).Respiratory tract and surgical wounds exhibited as the major infected sites,and the incidences were 59.3% and 28.9%,respectively.The rate of resistance to imipenem,piperacillin/tazobac,ceftazidime,Amikacin,Gentamicin,ampicillin,nitrofuranto and cefazolin was 32.6%,44.4%,66.7%,69.6%,83.7%,90.4%,96.3% and 100.0%,respectively.They were also resistant to other antibiotics to certain degree,126 stains showed multiple-resistance.Conclusions: Acinetobacter baumannii is the major opportunistic pathogenic bacteria in hospital infection which shows high rate of resistance to routine antimicrobial agents and even multiple drug resistance with important clinical impact.Antimicrobial agents should be used rationally to decrease multi-drug resistance.