Objective:To investigate the isolate situation and antibiotic resistance of Acinetobacter baumannii in a AAA hospital in recent three years,so as to know the resistant trend of Acinetobacter baumannii.Methods: From January 2009 to December 2011,isolation rate and resistance rate for 15 antibiotics of Acinetobacter baumannii in some AAA hospital were calculated to analyze the antibiotic resistance and variance trend of Acinetobacter baumannii.Results: The isolate rates of Acinetobacter baumannii were 7.4%,10.5% and 14.0% in 2009,2010 and 2011.The resistant rate variance of eleven antibiotics had significant difference(P0.05).The proportion of Acinetobacter baumannii resistant to more than five antibiotics were 19.4%,33.6% and 45.9%,showing uplifted trend year by year.Conclusion: Acinetobacter baumannii has become an important pathogen in clinical infection,whose resistance to common-used antibiotics rose year after year,and multi-drug resistance was more and more severe.