Abstract:ObjectiveTo analyze clinical distribution and change in drug resistance of Acinetobacter baumannii (A. baumannii) in 2009-2013, guide clinical rational antimicrobial use， and reduce healthcareassociated infection rate. Methods919 A. baumannii isolates were isolated from inpatients and outpatients in a hospital between January 2009 and December 2013, specimen and department sources, as well as change in drug resistance of A. baumannii were analyzed. ResultsA total of 10 273 pathogens were isolated from 2009 to 2013, the constituent ratio of A. baumannii in each year was 7.98%（n=93）,11.31%（n=155）,10.22%（n=185）,7.73%（n=217）, and 8.62%（n=269）respectively；the constituent ratio of imipenemresistant A. baumannii was 24.73%,38.06%,71.89%,64.52%, and 86.99% respectively；the main specimen source was sputum (83.68%); the major department sources were intensive care unit(ICU, 39.28%), department of neurology (20.78%）， and department of respiratory medicine（8.60%）. The resistant rate of A. baumannii to most antimicrobial agents increased, the resistant rates to imipenem and piperacillin / tazobactam increased from 24.73% and 4.44% in 2009 to 86.99% and 86.25% in 2013 respectively; resistant rate to sulphamethoxazole/trimethoprim decreased from 91.30% in 2009 to 27.14% in 2013; in 2013, except resistant rates to amikacin and sulphamethoxazole/trimethoprim were low (20.82% and 27.14% respectively), resistant rates to the other 11 kinds of antimicrobial agents were all ＞83.64%. ConclusionThe isolation rate of A. baumannii is high in this hospital, the main specimen source is sputum, the main department source is ICU; antimicrobial resistant rate of A. baumannii is high, prevention and control of infection and transmission of A. baumannii should be strengthened.