Abstract: AIM Discussion on ST segment elevation acute myocardial infarction (STEMI) patients in emergency percutaneous coronary intervention (PCI) in the use of IIb/IIIa receptor antagonist tirofiban influence for patients with infarction related artery blood flow. METHODS According to the order of treatment, 92 patients with STEMI were divided into study group and controlgroup with 46 cases in each group, the study group patients before PCI 1-3 h intracoronary use of tirofiban, controls directly for PCI, TIMI, vascular blood flow of infarction were compared between groups in PCI adverse events and prognosis and were stratified according to age group comparison. RESULTS Preoperative PCI, TIMI blood flow study group of grade 3 (32.61%) and grade 2 (43.48%) was higher than control group grade 3 and grade 2 constituent ratio. Distribution of blood flow in the study group was superior to that of TIMI in the control group (P<0.05). After PCI, TIMI blood flow study group of grade 3 (91.30%), grade 2 (8.70%) and control group grade 3 (84.78%), grade 2 (15.22%) distribution is relatively close. PCI operation in two groups after TIMI flow grade did not show significant difference. Before and after PCI, the study group of TMP flow grade distribution are significantly better than the control group (P<0.05). During PCI hospitalization, adverse events of two groups of patients and the incidence of postoperative complications and LVEF value comparing the differences between PLT reduction was not significant. Distribution of TIMI blood flow grading difference before and after operation in the >65-year-old group and <65 year-old group in PCI group was not significant. Distribution of blood flow and classification of TMP is less than or equal to the >65-year-old group of patients and <65-year-old group were significantly different (P<0.05). CONCLUSION Routine preoperative application of tirofiban in emergency PCI improved preoperative infarction vascular blood flow and myocardial perfusion. Myocardial reperfusion after operation showed a significant effect.