Abstract: Objective：To analyze the diagnostic ability of procalcitonin (PCT) for postoperative infection after gastric surgery by comparing the white blood cell count (WBC), C reactive protein (CRP) and PCT expression level in blood of patients with infection after gastric surgery. Methods：113 patients who underwent gastric surgery in General Surgery Departmentfrom January 2013 to June 2016 were selected, and divided into the postoperative infected group (n=45) and the postoperative uninfected group (n=68). The expression levels of WBC, CRP and PCT were compared at the first, third and seventh days after gastric surgery, and then the receiver operating characteristic curve (ROC) was used to analyze the value of WBC, CRP and PCT in the diagnosis of postoperative gastric infection. Results：The expression levels of WBC, CRP and PCT in the infected group were significantly higher than those in the uninfected group at first, third and seventh days after operation, and the differences were statistically significant (P<0.05). On the first day after gastric surgery, the ROC analysis to diagnose postoperative infection showed that the AUC of WBC, CRP and PCT were 0.748, 0.708， and 0.841， respectively. On the third day after gastric surgery, the ROC analysis showed that the AUC of WBC, CRP and PCT were 0.796, 0.811 and 0.826， respectively. On the seventh day after gastric surgery, the ROC analysis showed that the AUC of WBC, CRP and PCT were 0.784, 0.781， and 0.802， respectively. Conclusions：PCT is better than WBC and CRP in the diagnosis of postoperative gastric infection. PCT, WBC and CRP can supplement each other to provide comprehensive reference for the diagnosis of gastric infection after surgery.