ObjectiveTo study the incidences and risk factors of ventilatorassociated pneumonia (VAP)，and provide basis for prevention and control of VAP. MethodsPatients who used ventilators in two tertiary firstclass general hospitals from January 2006 to December 2011 were performed prospective monitoring; patients with VAP were  selected as VAP group, and without VAP were in nonVAP group (1∶1 ratio), risk factors for VAP were analyzed. ResultsA total of 2 550 patients who used ventilators were monitored, 475 cases of VAP occurred, the total number of ventilation days were 32 623, incidence rate of VAP was 14.56‰. Univariate analysis showed that risk factors for VAP were history of recurrent respiratory tract infection, use of broad spectrum antimicrobial agents within one month, multiple hospitalization, coma, hypoproteinemia, intubation again after failure in ventilator weaning, use of glucocorticoid, mechanical ventilation for >5 days, regurgitation, and poor oral hygiene. Multivariate logistic regression analysis showed that independent risk factors for the occurrence of VAP were  coma (OR 95% CI：1.38-2.93), hypoproteinemia (OR 95% CI：1.12-2.10), use of glucocorticoid (OR 95% CI：1.10-2.24), intubation again after failure in ventilator weaning (OR 95% CI：2.14-4.74), mechanical ventilation＞5 days (OR 95% CI：2.55-4.83), regurgitation (OR 95% CI：1.24-2.77), and poor oral hygiene (OR 95% CI：1.72-3.74). ConclusionIncidence of VAP is high, and risk factors are multiple, comprehensive intervention measures (proper oral hygiene, headofbed elevation, timely assessment of withdrawal of respirator, and improving nutritional status) should be taken, so as to reduce the incidence of VAP.