ObjectiveTo investigate the change in distribution and antimicrobial resistance of Acinetobacter baumannii(AB) in an intensive care unit(ICU), and provide basis for rational use of antimicrobial agents in the clinical practice.MethodsUsing retrospective investigation study, data about pathogenic bacteria isolated from patients who were hospitalized in ICU in 2010-2014 were collected, distribution and antimicrobial resistance of AB were statistically analyzed.ResultsA total of 3 807 bacterial strains were isolated from ICU patients in 2010-2014, 488(12.82%) of which were AB, isolation rate increased from 6.94% in 2010 to 17.33% in 2014 （χ2=45.58，P＜0.01）. AB was mainly isolated from sputum, accounting for 72.13%, followed by wound secretion, blood, catheter, urine and so on; AB had the lowest resistance rate to amikacin(<30%), resistance rates to imipenem and meropenem increased significantly year by year (value of trend χ2 test were 42.99 and 53.91 respectively, both P＜0.001);  resistance rates of AB to other antimicrobial agents were all>50%.ConclusionDetection rate and antimicrobial resistance rate of AB increased year by year, clinical surveillance on bacterial resistance should be paid more attention, patients should be isolated by effective measures, so as to control and prevent the prevalence of AB in ICU.