Abstract: OBJECTIVE To investigate the characteristics of pathogens isolated from gastrectomy patients with postoperative infection and analyze the risk factors. METHODS The gastrectomy patients who were treated in Xinyang Center Hospital from Nov 2016 to Nov 2019 were recruited as the study objects, 65 patients who had postoperative infection were assigned as the infection group, and 65 patients who did not have infection were set as the control group. A retrospective epidemiological questionnaire was designed to collect the data of the patients, including age, gender, place of residence, medical history, smoking status, pathological types, types of surgery, culture of pathogens, inflammatory factors and course of disease. The characteristics of pathogens and risk factors for the infection were observed. RESULTS A total of 86 strains of pathogens were isolated from 65 patients in the infection group, 58.14% of which were gram-negative bacteria, 37.21% were gram-positive bacteria, and 4.65% were fungi. Klebsiella pneumoniae (27 strains), Staphylococcus aureus (21 strains) and Pseudomonas aeruginosa (15 strains) ranked the top 3 species of pathogens, accounting for 31.40%, 24.42% and 17.44%, respectively. Univariate analysis showed that the no less than 65 years of age, BMI no less than 24.0 kg/m², residence in rural area, smoking history, type 2 diabetes mellitus, Helicobacter pylori infection, albumin less than 30.0 g/L and length of hospital stay no less than 20 days were the influencing factors for the postoperative infection in the gastric cancer patients, and there were significant differences between the two groups (P<0.05). Logistic regression analysis indicated that OR values of the preoperative albumin, surgeral mode and the length of hospital stay were more than 1 (P<0.05). CONCLUSION K.pneumoniae, S.aureus and P.aeruginosa are dominant among the pathogens causing the postoperative infection in the gastric cancer patients. There are a variety of influencing factors for the postoperative infection; the preoperative albumin, surgeral mode and the length of hospital stay are the independent risk factors for the postoperative infection in the gastric cancer patients.