OBJECTIVE： To study the effects of Danhong injection （DHI） on myocardial protection of acute myocardial infarction （AMI） model rats. METHODS： Totally 30 rats were randomly divided into sham operation group （normal saline， im）， model group （normal saline， im） and DHI group （0.76 mL/kg， im） according to random number table method， with 10 rats in each group. Except for sham operation group， AMI model was induced by ligation of left anterior descending coronary artery in other groups. After modeling， rats were given relevant medicine once a day， for consecutive 14 d. 24， 48 h after operation， the serum lsevels of LDH， CK and CK-MB were determined by automatic biochemical analyzer. 14 d after medication， the serum levels of IL-1β， CRP and TNF-α were determined by ELISA. Echocardiography was applied to observe the changes of left ventricular wall movement of rats in each group. Based on HE staining and MASSON staining， morphological analysis was performed for myocardial. RESULTS： Compared with sham operation group， the serum levels of LDH， CK and CK-MB in model group were increased significantly 24 h after operation （P＜0.05）. 14 d after medication， the serum levels of IL-1β， CRP and TNF-α were increased significantly （P＜0.05）； there was almost no fluctuation in the anterior wall of the left ventricle； in the myocardial tissue， only a small number of myocardial cells survived， while cell volume increased and arranged loosely； nuclear condensation or dissolution were also found； the percentage of myocardial infarction area was increased significantly （P＜0.05）. Compared with model group， the serum levels of LDH， CK and CK-MB in DHI group were decreased significantly 48 h after operation （P＜0.05）. Serum levels of IL-1β， CRP and TNF-α were decreased significantly 14 d after medication （P＜0.05）. The degree of left ventricle dilation decreased significantly， and ventricular wall thickened and fluctuated； myocardial fibrosis decreased， necrosis of myocardial cells decreased， and the percentage of myocardial infarction area decreased significantly （P＜0.05）. CONCLUSIONS： DHI plays the role of improvement of AMI by decreasing the levels of myocardial enzyme spectrum indexes and inflammatory factors and inhibiting myocardial fibrosis.