Abstract: Objective To analyze the risk factors of ventilator-associated pneumonia (VAP) in elderly patients, propose appropriate precautions of VAP and control hospital infection effectively. Methods A retrospective analysis was performed in aged patients (≥80 years) who were treated with mechanical ventilation (MV) over 48 hours in Chinese PLAgeneral Hospital from January 2011 to October 2015.Patients were divided into two groups by with or without VAP, of which there were 245 males and 185 females, suffering from respiratory diseases, cardiovascular diseases, or nervous system diseases.The clinical data about patients in two groups were compared and analyzed. Results Of the 430 patients with mechanical ventilation, VAP occurred in 74 cases with the incidence of 17.21%.Univariate analysis showed that there were significantly difference ingender, length of hospital stays, length of ICU stay, ways of mechanical ventilation, duration of mechanical ventilation, duration of combined application of antibacterials, number of combined application of antibacterials, pH, PaO₂between two groups (P＜ 0.05).Logistic regression analysis showed the independent risk factors for VAP in elderly patients weregender (OR=14.991, P=0.000), length of hospital stay (OR=2.855, P=0.008), duration of mechanical ventilation (OR=4.314, P=0.001), the use of acid-suppressive agent (OR=2.329, P=0.026), duration of combined application of antibacterials (OR=2.483, P=0.005), pH (OR=0.347, P=0.000), PaO₂(OR=2.139, P=0.003). Conclusion The occurrence of VAP is associated with varieties of factors.Protective measures targeted to those factors should be taken during the daily care to elderly patients with mechanical ventilator.