AIM: To analyze the relation between stress hyperglycemia and intestinal mucosal barrier function after gastrectomy of stomach neoplasms. METHODS: 71 patients with gastric carcinoma and prepared for radical operation were selected, 29 of them with stress hyperglycemia after surgery were the observation group, while the others were included the control group. The fasting blood of patients before surgery and 2 h, 12 h, 24 h, 36 h, 48 h, 72 h, 120 h after surgery were extracted to detect fasting plasma glucose by blood sugar analyzer and serum D-lactic acid. Diamine oxidase (DAO) level was detected by ELISA kits. Furthermore, the urinary lactulose and mannitol ratio (L/M) was also detected at the same time. RESULTS:Both groups and times had effect on blood sugar, urine L/M, D-lactic acid and DAO level (P<0.05), and there was no interaction between (P>0.05). In terms of the trend, the blood glucose level increased after treatment, and peaked at 24 h, and the observation group was higher than the control group at 12 h, 24 h, 36 h and 72 h after surgery (P<0.05). The L/M level increased after treatment, and peaked at 72 h, and the observation group was higher than the control group at each time point after surgery (P<0.05). The serum D-lactic acid and DAO level increased after treatment, and the control group peaked at 72 h, while the observation group increased all the time, and at most time, the observation group was higher than the control group (P<0.05). Before treatment and 24h after surgery, the blood glucose levels were positively correlated with L/M, D-lactic acid and DAO levels (P<0.05); 72h after surgery, the blood glucose levels were positively correlated with L/M and DAO levels (P<0.05); 120h after surgery, there was no significant correlation between blood glucose levels and the other indexes (P> 0.05). CONCLUSION: There is certain correlation between stress hyperglycemia and intestinal mucosal barrier function injury after gastric cancer radical surgery, and it is of great significance for intestinal function recovery to monitor and control blood glucose after surgery.