Aim To investigate the effect of asiatic acid on acute myocardial infarction (AMI) rats and its mechanism. Methods Healthy SD rats were used to establish acute myocardial infarction model by ligation of anterior descending branch of left coronary artery, then the successful model rats were randomly divided into model group, low, middle and high dose of asiatic acid group, 10 rats in each group. Sham group only threaded without ligation. Asiatic acid group were given asiatic acid 25 mg/kg, 50 mg/kg and 100 mg/kg by gavage, once a day for 28 consecutive days. The changes of ST segment of electrocardiogram were recorded before operation, immediately after operation, 1,3, 7,0, 4,1 and 28 days after administration. Myocardial apoptosis was detected by TUNEL, morphological and pathological changes of myocardial tissue were observed by HE staining, serum lactate dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB) and superoxide dismutase (SOD) and malondialdehyde (MDA) were detected by ELISA. The expression of Nrf2, HO-1 and NF-κB mRNA were determined by RT-PCR, the expression of Nrf2, HO-1 and NF-κB protein was determined by Western blot. Results The electrocardiogram ST segment of acute myocardial infarction rats was significantly elevated after model establishment, the electrocardiogram ST segment of myocardial infarction rats after asiatica acid treatment showed a downward trend in varying degrees (P＜0.05). HE staining showed that myocardial cells in the model group were disordered and infiltrated with a large number of inflammatory cells, and the nuclei dissolved, disappeared or even necrosed. The degree of myocardial cell disorder, the phenomena of cell nucleolysis and the infiltration of inflammatory cells were alleviated in all dose groups of asiatica acid. Compared with sham group, apoptotic myocardial cells increased significantly (P＜0.05), serum levels of CK-MB, LDH, MDA decreased significantly and SOD increased significantly (P＜0.05), the expression of Nrf2, HO-1 mRNA and protein decreased significantly (P＜0.05), the expression of NF-κB mRNA and protein increased significantly in the model group (P＜0.05). Compared with model group, apoptotic myocardial cells decreased significantly (P＜0.05), serum levels of CK-MB, LDH, MDA increased significantly and SOD decreased significantly (P＜0.05), the expression of Nrf2, HO-1 mRNA and protein increased significantly (P＜0.05), the expression of NF-κB mRNA and protein decreased significantly in all dose groups of asiatica acid (P＜0.05). Conclusion Asiatic acid can improve myocardial injury in rats with acute myocardial infarction, which may be achieved by regulating Nrf2/HO-1 and NF-κB signaling pathways.