To observe the safety and short-term outcomes of domestic tirofiban in patients with ST elevation acutecoronary syndrome(STEACS) undergoing percutaneous coronary intervention (PCI).Methods:Two hundred and seventy-seven patients with STEACS were enrolled in the study and divided into two groups:the tirofiban group (n=140) and the control group(n=137).TIMI grade,bleeding rate in both groups were investigated and compared before and after PCI. Major adverse cardiac events were also recorded in hospital and during 3 months’ follow-up.Results:Ninty-one percent of patients in the tirofiban group compared with 81% in the control group obtained TIMI grade 3 flow (P<0.05).There was no significant difference in the incidence of bleeding between two groups(P>0.05).There were no serious bleeding complications and MACE in-hospital and follow-up period.Conclusion:Additional use of tirofiban on the basis of conventional drug is safe and effective in thetreatment of high-risk ST elevation acutecoronary syndrome.