Abstract: Objective To investigate the incidence of upper gastrointestinal bleeding in coronary heart disease patients treated with dual antiplatelet therapy, and to analyze its influencing factors. Methods A retrospective analysis was performed to review the clinical materials of 100 patients with coronary heart disease, and were divided into control group and study group according to different medication regimens. The control group was treated with aspirin, and the study group was additionally treated with clopidogrel bisulfate based on the control group. The incidence of upper gastrointestinal bleeding, coagulation indexes［prothrombin time(PT), and activated partial thromboplastin time(APTT)］before and after treatment, and platelet aggregation rate were compared, and the influencing factors of digestive bleeding were analyzed. Results The incidence of upper gastrointestinal hemorrhage in the study group was 34.29%, which was higher than 12.31% in the control group, and the difference was significant(P<0.05); there were no significant differences between the two groups before treatment in PT, APTT and platelet aggregation rate(P>0.05); after treatment, the levels of PT and APTT in the study group were significantly higher than that in the control group, and the platelet aggregation rate was significantly lower than that in the control group(P<0.05). Seventy years of age and above, history of gastrointestinal disease, chronic renal insufficiency, more than 3 months of medication time, history of diabetes and alcoholism were important influencing factors for upper gastrointestinal bleeding(P<0.05). Conclusion The risk of upper gastrointestinal bleeding caused by double antiplatelet therapy in patients with coronary heart disease is high. Therefore, it is necessary to strengthen prevention and control measures during clinical medication to reduce the risk - of bleeding and ensure the safety of medication.