Objective：To compare the efficacy and safety between Fondaparinux and low molecular weight heparin（LMWH） in treat－ing acute myocardial infarction（AMI） without revascularization at early stage. Methods:Three hundred and two patients with AMI without revascularization at early stage were randomly divided into Fondaparinux group（152 cases） and LMWH group（150 cases）. The cardiovascular event and bleeding incidences within 7 d and 30 d after the treatment in both group were observed. Results：The incidences of cardiovascular events （angina，recurrent myocardial infarction，death，vicious arrhythmia，heart failure） within 7 d in Fondaparinux group were obviously lower than those in LMWH group（8.6％ vs. 18.7％，2.6％ vs. 8.7％，2.6％ vs. 8.0％，3.6％ vs. 10.0％ and 11.8％ vs. 21.3％）. The incidences of major adverse cardiac events（recurrent myocardial infarction，death，refractory myocardial ischemia） within 30 d in Fondaparinux group were obviously lower than those in LMWH group（3.9％ vs. 10.0％，3.9％ vs. 10.7％，3.3％ vs. 13.3％ and 8.6％ vs. 21.3％）. There was no significant difference in incidences of bleeding events between the two groups. Conclusions：Fondaparinux can significantly reduce cardiovascular events without increasing bleeding events in patients with AMI but not undergoing revascularization at early stage.