Objective To 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.Methods From January 2012 to December 2013,HAP patients were conducted retrospective co-hort study,risk factors for MDRO-HAP and rationality of antimicrobial use were analyzed.Results A total of 110 cases of HAP occurred in ICU,63 cases (57.27%)were MDR-HAP.Logistic regression analysis revealed that re-cent 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 be-tween 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 ).Conclusion Patients 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.