ObjectiveTo assess the risk factors of multidrugresistant organism(MDRO) healthcareassociated pneumonia(HCAP). MethodsThe casecontrol study was conducted in patients admitted to 22 hospitals in 4 cities  between April 1, 2013 and December 31, 2013,patients with  HCAP  caused by MDRO (MRSA,MDRPA,MDRAB,ESBL KP, ESBL E.coli）(drugresistant group )and drugsensitive organisms （MSSA, PA,AB,KP,E.coli）(drugsensitive group )were surveyed  . Univariate and multivariate statistical analysis methods were used to evaluate the risk factors for MDRO HCAP. The prognosis, cost and length of hospital stay between drugresistant group and drugsensitive group were compared . ResultsA total of 1 656 patients were included in the study ,including 43 patients （2.60%）with mixed infection caused by both drugresistant and drugsensitive organisms ;there were 927 cases （55.98%）in drugresistant group and 772 cases（46.62%）in drugsensitive group . Logistic regression model revealed that admission to ICUs (OR 95%CI：1.55［1.14-2.11］), mechanical ventilation (OR 95%CI：1.45［1.15-1.84］), arteriovenous catheterization (OR 95%CI：1.29［1.02-1.63］）, fiberbronchoscopy (OR 95%CI：1.46［1.02-2.09］）, antimicrobial use(OR 95%CI：1.63［1.20-2.22］） , chronic lung diseases (OR 95%CI：1.54［1.13-2.10］）, and chronic cardiovascular and cerebrovascular diseases (OR 95%CI：1.42［1.15-1.74］）were independent risk factors for MDRO HCAP .Compared with drugsensitive group , drugresistant group prolonged length of hospital stay by an average of 5.89 days, increased hospitalization and  antimicrobial expense by ￥40 739.30 and ￥2 805.80 respectively; prognoses was worse, risk factor was 1.66fold of drugsensitive group（OR 95%CI：1.16-2.35）.ConclusionAdmission to ICUs, invasive operations, antimicrobial use, chronic lung diseases and chronic cardiovascular and cerebrovascular diseases can increase the risk of MDRO HCAP .