Abstract: Objective To analyze the risk factors and the distribution of pathogenic bacteria of ventilator-associated Pneumonia (VAP) with different endotracheal intubation access in elderly patients, in order to provide evidences for prevention and therapy of VAP. Methods Clinical data about aged patients (80 years or over) who had received mechanical ventilation over 48 hours from January 2011 to December 2015 in Chinese PLA General Hospital were retrospectively anayzed. Results Totally 390 cases were included in this study. Of the 240 patients underwent tracheal intubation, 39 cases were diagnosed as VAP with the incidence of 16.25%; Of the 150 patients underwent tracheotomy, 34 patients had VAP with the incidence of 22.67%. Gram-negative bacteria were the major pathogens in elderly patients with different mechanical ventilation access, and the preceding three were Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia. Logistic regression analysis showed that the risk factors of VAP for elderly patients with tracheal intubation were COPD (OR=0.234, 95% CI=0.058-0.936, P=0.040), duration of mechanical ventilation (OR=5.258, 95% CI=2.037-13.572, P=0.001), the use of hormone (OR=3.047, 95% CI=1.391-6.673, P=0.005). Number of combined application of antibacterials was negatively related to the occurrence of VAP for elderly patients with tracheotomy (OR=0.101, 95% CI=0.013-0.783, P=0.028). Conclusion Gram-negative bacteria were the most common pathogens of VAP. Risk factors of ventilator-associated pneumonia with different mechanical ventilation access are different.