Abstract: OBJECTIVE To analyze the risk factors of ventilator-associated pneumonia patients infected with Acinetobacter baumannii(ABA) in ICU by multiple regression analysis, and formulate preventive measures. METHODS From Mar. 2013 to Mar. 2016, drug sensitivity and risk factors of 126 cases of ventilator-associated pneumonia patients infected with AB in ICU were analyzed retrospectively. RESULTS AB showed high resistant rates to ampicillin and gentamicin, and the resistant rates were more than 90%, and high sensitivity to imipenem and meropenem, and the resistant rates were lower than 20%. Among these, 85 cases showed 3 or more kinds of antibiotics resistance and classified as pan-resistance. Single factor analysis showed that hospital stay, mechanical ventilation mode, the use of corticosteroids, indwelling stomach tube, the use of carbapenem antibiotics and using three or more kinds of antibiotics were significantly correlated with the development of pan-resistance of AB in ventilator-associated pneumonia patients(χ²=20.292, 10.414, 7.524, 7.810, 9.760 and 11.635,P<0.05). Logistic regression model analysis showed that mechanical ventilation, indwelling tube, and using three or more kinds of antibiotics were independent risk factors of pan-resistance of AB in ventilator-associated pneumonia patients(OR=6.527, 6.337, and 5.467, P<0.05). CONCLUSION Pan-resistance of AB is serious in ventilator-associated pneumonia patients of ICU, and mechanical ventilation, indwelling tube, and using three or more kinds of antibiotics are the independent risk factors. Medical staff should avoid the further spread of infections and drug resistance of ABA.