Objective: To observe the therapeutic effect of intravenous thrombolysis of recombinant streptokinase (r SK) on acute myocardial infarction (AMI) and its safety. Methods: Twenty patients with AMI received r SK for thrombolysis.The reopening rate of infarct related artery,side effect and the fatality rate in hospital were observed. Results: The reopening rate of infarct related artery was 75%. The incidence of slight hemorrhage, fever, low blood pressure,which could be corrected in short time, was 5%, 15%, 15%, respectively. The fatality rate 5 weeks after AMI was 10%. Conclusion: The therapeutic effect of r SK in the thrombolytic therapy of AMI is definite and the safety is fine.