Objective To analyze the risk factors for ventilator-associated pneumonia(VAP)in children after cardiopulmonary bypass(CPB).Methods Between January 2003 and June 2010,116 consecu tive cases receiving postoperative ventilation for more than 48 hours were included in this study.The patients were assigned into a VAP group(n =57)and non-YAP group(n =59).Univariate and multivariate logistic regression analysis were used to identify the risk factors.Results The overall incidence of VAP was 4.18％(57/1 365).The mortality of VAP was 26.32％(15/57).Univariate risk factors included severe pulmonary hypertension,CPB time,aortic cross-clamping time,secondary CPB support,plasma albumin,low ratio of ar terial oxygen tension to inspired oxygen fraction(PaO2/FiO2),mechanical ventilation time,the volume of postoperative drainage per kilogram of body weight,re-intubations,tracheotomy,gastric tube retention,pre vention of stress ulcer.Multivariate logistic regression analysis showed that risk factors included CPB time≥150 min,mechanical veritilation time ≥4 d,the volume of postoperative drainage per kilogram of body weight ≥ 18 ml and tracheotomy.A total of 90 pathogens were obtained by sputum culture in 57 VAP patients.There were 54 cases(60.0％)gram negative bacilli,32 cases(35.6％)of gram positive bacilli and 4 cases (4.4％)of eumycetes.Conclusion These results suggest that the patients with risk factors described above need more careful and postoperative surveillance and management.