Abstract: OBJECTIVE To analyze the characteristics of distribution of pathogens causing postoperative infections in gastrointestinal malignant tumor patients complicated with diabetes so as to provide guidance for clinical prevention, diagnosis, and treatment. METHODS A total of 147 gastrointestinal malignant tumor patients complicated with diabetes who were treated in the hospital from Jan 2012 to Jan 2015 were randomly recruited as the study objects, the characteristics of distribution of the pathogens causing the infections were observed, and the risk factors for the infections were analyzed. RESULTS The infections occurred in 54 of 147 patients, with the infection rate 36.73%.Totally 54 strains of pathogens were isolated, including 14 (25.93%) strains of gram-positive bacteria, 35 (64.81%) strains of gram-negative bacteria, and 5 (9.26%) strains of fungi.The gram-negative bacteria were highly resistant to penicillins, while the drug resistance rates to piperacillin drugs were relatively low.The gram-positive bacteria were highly susceptible to vancomycin; the drug resistance rate of the Candida albicans was relatively low, and only 1 strain was resistant to amphotericin B.The risk factors for the infections included the age, operation duration, antibiotics prophylaxis, and bleeding amount (P＜0.05). CONCLUSION The gram-negative bacteria are dominant among the pathogens causing the postoperative infections in the gastrointestinal malignant tumor patients complicated with diabetes, and the Escherichia coli is the predominant species of the pathogens.It is necessary for the hospital to carry out the early prevention based on the physical condition of the patients and reasonably use antibiotics so as to reduce the infection rate.