Objective:To discuss the characteristic and risk factors of ventilator-associated pneumonia in mechanical ventilation patients. Methods: The clinical data of patients with mechanical ventilation in ICU from Jan. 2001 to Jun. 2003 were retrospectivly analyzed. Totaly 63 cases were collected,31 patients of them have VAP. The number of non-VAP patients is 32. Results:①The VAP group has a obviously longer period of mechanical ventilation than the non-VAP group[ 17. 3 ± 15. 3)d vs (6. 1 ±. 8)d P0. 01], In the VAP group,41. 9% patients has a period of mechanical ventilation over 10 days, while 9.4% patients of non VAP group has an over 10 days ventilation period. The difference between their is significant. ②31.8% patients in the VAP group were administrated with nutrition support, which is significantly different from the non VAP group (71. 8%)(P = 0. 004).③Logistic analysis suggests that mechanical ventilation time and nutrition support are two risk factors of VAP (using occurrence of VAP as variable). Conclusion:Compared with the non-VPA group.the VAP group has relativly longer period of mechanical ventilation,and lower proportion of proper nutrition support. These may be the two risks factors of VAP.