Objective:To investigate the specimen source,clinical distribution and antimicrobial resistance of Acinetobacter baumannii isolated from Affiliated Hospital of Xuzhou Medical College from 2012 to 2014. Methods:Acinetobacter baumannii isolates were identified by BD Phoenix 100 automatic microbial identification system (USA). The susceptibility testing was performed by Kirby-Bauer diffusion method,and the antimicrobial susceptibility data were analyzed by WHONET 5.6 software. Results:The isolated Acinetobacter baumannii of 2012-2014 strains were 1213,1492 and 1712,respectively,accounting for 53.5%,44.4% and 39.9% of the non-fermentative gram negative bacilli,respectively. The Acinetobacter baumannii strains were mainly isolated from sputum specimens (89.2%),and the Acinetobacter baumannii infection mainly distributed in emergency intensive care unit (ICU)(37.5%). Except for levofloxacin,amikacin,polymyxin and sulfamethoxazole compound,the resistance of Acinetobacter baumannii to cephalosporins,carbapenem,quinolones and aminoglycoside reached more than 80.0% in 3 years. The resistance rate of imipenem increased from 83.1% in 2012 to 87.1% in 2013,subsequently,the rate decreased to 82.8% by 2014. Likewise,the resistance rates of meropenem were 84.9%,87.7% and 85.1% from 2012 to 2014,respectively. Nevertheless,the resistance rate of polymyxin was the lowest,ranging from 1.5% to 2.9%. Conclusion:Antimicrobial resistance rate of Acinetobacter baumannii isolated from 2013 exhibited an apparent increasing compared to that from 2012,and then decreased in 2014,but still very serious,which should be paid more attention to. Therefore,monitoring of the resistant of Acinetobacter baumannii and the management of clinical rational use of antimicrobial drugs should be strengthened.