Abstract: Objective To explore the effect of intravenous thrombolysis using reteplase combined with tirofiban on elderly patients with acute ST-segment elevation myocardial infarction(STEMI) and its influence on coagulation function. Methods Totally 116 elderly STEMI patients admitted to Danzhou Traditional Chinese Medicine Hospital and Hainan Western Central Hospital from January 2015 to October 2018 were selected and assigned into observation group(n=58) and control group(n=58) according to random number table method. The control group received reteplase thrombolytic intervention, while the observation group received tirofiban combined with reteplase thrombolytic intervention. Vascular recanalization rate, adverse cardiovascular events, bleeding events and thrombin time(TT), prothrombin time(PT), activated partial thromboplastin time(APTT) and fibrinogen(FIB) levels were compared between the two groups. Results The recanalization rates at 60, 90 and 120 minutes after thrombolysis in the observation group were significantly higher than those in the control group(60 min, 67.2% vs 36.2%; 90 min, 81.0% vs 63.8%; 120 min,93.1% vs 72.4%; P< 0.05, respectively). The incidences of post-infarction angina pectoris(8.6% vs 22.4%), heart failure(3.4% vs 15.5%) and re-infarction(1.7% vs 12.1%) in the observation group were significantly lower than those in the control group(all P<0.05). There was no significant difference in the incidence of total bleeding events between the observation group and the control group during hospitalization(P> 0.05). After treatment, the levels of TT, PT and APTT in the two groups were significantly longer than those before treatment, and the levels of TT, PT and APTT in the observation group were significantly higher than those in the control group(P< 0.05). After treatment, the level of FIB in the two groups was significantly lower than that before treatment, and the level of FIB in the observation group was significantly lower than that in the control group(P< 0.05). Conclusion Reteplase combined with tirofiban is superior to reteplase alone in the treatment of STEMI in elderly, and it can improve the coagulation function of patients.