<正> The purpose of this study is to evaluate efficacy and safety of intravenousrecombinant tissue-type plasminogen activator(rt-PA) in treatment of acutemyocardial infarction(AMI).Fifty-three patients with AMI admitted to ourhospital from April 1995 to December 1997 were confumed to the inclusion andexertion criteria of thrombolytic therapy.The patients in Group B and to receivert-PA intravenous(i.v.) blous 0mg in five rain followed by an 40mg i.v.infusion over 55 min.or over 85 min.The clinical criteria of reperfusion wereevaluated.The reperfusion rate of Group A was 67.86% and 92.0% of Group B.The total reperfusion rate was 79.25% in 53 patients who treated with rt-PA.Hypotension,mild bleeding rigor occurred respectively in 11.32%.13.20% and1.87% of patients with rt-PA,rt-PA is a safe and effective thrombolytic agent.Total dose of 50mg of rt-PA is suitable to use among Chinese.