ObjectiveTo compare postoperative pulmonary infection in patients undergoing surgical operation at different surgical opportunities. MethodsPatients who underwent surgical operation in a hospital from January to December 2014 were surveyed retrospectively, patients’ data were reviewed, patients with postoperative pulmonary infection were compared. ResultsA total of 20 343 surgical patients were investigated, 227(1.12%) had postoperative pulmonary infection. Postoperative pulmonary infection rate in patients undergoing emergency operation was higher than that of selective operation (5.13% vs 0.70%, χ2=307.49，P＜0.001）. Postoperative pulmonary infection rates in patients undergoing emergency neurosurgical, general surgical, and cardiothoracic surgical operation were all higher than selective operation(all P<0.001). Among patients with pulmonary infection following emergency operation, the proportion of those who aged <60 years, with preoperative irrational antimicrobial use, cardiovascular disease, hypertension, and tracheotomy were all higher than those who received selective operation(all P<0.05); the proportion of patients with cancer is lower than that of elective surgery patients（P＜0.05）. ConclusionPostoperative pulmonary infection rate in patients undergoing emergency operation is higher than selective operation, postoperative pulmonary infection rates in patients undergoing emergency neurosurgical, general surgical, and cardiothoracic surgical operation are high. Patients with cardiovascular disease and hypertension are the focus of protection; for elective surgery, cancer patients are the focus of protection.