Abstract: OBJECTIV To explore the risk factors for postoperative infections in gastric cancer patients and observe the association between the change of cellular immune level and the postoperative infections so as to provide guidance for prediction of the postoperative infections. METHODS A total of 30 patients who underwent gastrectomy in hospitals from Apr 2014 to Mar 2016 (the gastric cancer group) were randomly extracted as the study objects. The risk factors for the postoperative infections in the gastric cancer patients were analyzed, the levels of T lymphocyte subsets and serum immunoglobulin (IgM, IgG, IgA) of the gastric cancer group were dynamically monitored, and the clinical value of the detection indexes for the postoperative infection was evaluated. RESULTS Of the 30 gastric cancer patients, 9 had the postoperative infections, with the infection rate 30.0%. The independent risk factors for the postoperative infections in the gastric cancer patients included the age, smoking, scope of surgery, preoperative blood transfusion volume, and pathological stage, among which the preoperative blood transfusion volume (more than 3U) was the highest risk. The CD₄⁺ level of the gastric cancer group dropped to the lowest level after the surgery for 6-8 days and then rose to the normal level, and there was significant difference in the CD₄⁺ level before and after the surgery (P＜0.05). CONCLUSION The independent risk factors for the postoperative infection in the gastric cancer patients include the age, smoking, scope of surgery, preoperative blood transfusion volume, and pathological stage, which are the key points for clinical control and prevention. In the view of fluctuation trend of the CD₄⁺ level after the surgery for different time periods, the reduced level of CD₄⁺ may be the direct factor that induce the postoperative infection. It is of clinical significance for the prediction of the postoperative infection to intensify the detection of clinical cellular immune level.