Abstract: OBJECTIVE To explore the predictive value of physiological and operative severity score in the enumeration of mortality and morbidity (POSSUM)for pulmonary infection in hospitalized patients with spinal surgery, so as to provide guidance for later clinical treatment. METHODS A total of 371 cases of hospitalized patients with spinal surgery were selected as the research objects from Aug. 2014 to Aug. 2016 in our hospital. Totally 245 patients aged less than 45 years were set as younger group, and 126 patients aged 45 or above were set as elderly group. POSSUM scoring system was used to predict pulmonary infection in the two groups of patients. RESULTS The operation time, blood loss during operation, perioperative blood transfusion and hospitalization days of younger group were significantly lower than those in elderly group, surgery in younger group and the physiological score were less severe than those in elderly group, and the differences were statistically significant (P<0.05). The predicted incidence of pulmonary infection in younger group was higher than that of elderly group, the true incidence of pulmonary infection in younger group was lower than that of elderly group, the true incidence of pulmonary infection in younger group was significantly lower than the predicted incidence, and the differences were statistically significant (P< 0.05). There was no significant difference in the true incidence and predicted incidence of pulmonary infection in elderly group. Totally 15 strains of pathogenic bacteria were isolated from infected patients of younger group, and 9 strains from infected patients of elderly group. The common infections of the two groups of patients were Escherichia coli and Enterococcus faecalis. CONCLUSION The POSSUM score can predict hospitalization incidence of pulmonary infection in patients with spinal surgery, and the prediction of the elderly group of patients is with higher accuracy than the younger group.