ObjectiveTo analyze risk factors and antimicrobial use for hospitalacquired pneumonia (HAP) due to multidrugresistant organisms (MDROs) in an intensive care unit(ICU),  so as to perform risk assessment and  guide antimicrobial use.MethodsFrom January 2012 to December 2013, HAP patients were conducted retrospective cohort study, risk factors for MDROHAP and rationality of antimicrobial use were analyzed. ResultsA total of 110 cases of HAP occurred in ICU, 63 cases (57.27%) were MDRHAP. Logistic regression analysis revealed that recent hospital stay ≥5 days (OR=19.94)， transference from other hospitals (OR=19.33), infection type of lateonset HAP (OR=7.98)， and antimicrobial use in recent 90 days (OR=3.42) were independent risk factors for MDRHAP. Initial empirical antiinfective treatment revealed that there were no significant difference in timing of antimicrobial administration within 24 hours  after clinical diagnosis was confirmed, and rationality of antimicrobial selection between MDRHAP group and nonMDRHAP group (both P>0.05); The  isolation rate of pathogens in MDRHAP group was lower than nonMDRHAP group (73.02% vs 91.49% P<0.05).Targeted antimicrobial therapy revealed that there were no significant difference in selection， dosage, and frequency of antimicrobial use between two groups(all P>0.05); the rationality rate of therapy course in MDRHAP group was higher than noMDRHAP group, but rationality rate of combination use of antimicrobial agents was slightly lower than the latter(both P<0.05).ConclusionPatients in ICU should be conducted risk factor assessment, and according prevention and control measures should be formulated, so as to reduce the occurrence of MDRHAP，health care workers should standardized the initial empirical antiinfective treatment.