Abstract: Objective  To explore the risk factors of postoperative pulmonary infection in patients with lung cancer（PPILC）. Methods A total of 851 lung cancer patients who underwent surgical treatment from March 2011 to February 2018 were selected as the research subjects. The risk factors of PPILC were analyzed by multivariate logistic regression analysis after isolation and identification of pathogenic bacteria. Results There were 60 patients with postoperative pulmonary infection，and 86 pathogenic bacteria were isolated，of which Gram-negative bacteria accounted for 60.5%，mainly Pseudomonas aeruginosa and Klebsiella pneumonia; Gram-positive bacteria accounted for 33.7%，mainly Staphylococcus aureus and Staphylococcus epidermidis; fungus accounted for 5.8%. Multivariate logistic regression analysis showed that the influencing factors of PPILC included TNM stage，smoking，age，merged diabetes，chronic obstructive pulmonary disease，invasive operation，operation time，intraoperative bleeding volume，mechanical ventilation time，total amount of postoperative thoracic drainage，postoperative hemoglobin level，postoperative serum albumin level，duration of thoracic drainage，prophylactic use of antibiotics and length of stay（P<0.05）. Conclusions Age，smoking，concomitant diabetes，chronic obstructive pulmonary disease，and TNM staging can affect the occurrence of PPILC. In clinical practice，more attention should be paid to the prevention and treatment of postoperative pulmonary infection in patients with the above risk factors. 

Key words: Lung cancer, Pulmonary infection, Influencing factors