Aim To investigate the effect of Ligustrazine injection on myocardial injury markers and cardiac function in rats with acute myocardial infarction. Methods 36 male SD rats were selected as experimental animal and randomly divided into control group, model group and intervention group, 12 animals in each group. Model group and intervention group were used to establish acute myocardial infarction (AMI) model, and intervention group was treated with ligustrazine injection. At 1 week and 3 weeks after intervention, the cardiac color doppler echocardiography was performed to measure the cardiac function, and serum was collected for the determination of myocardial injury markers and oxidative stress indexes. Results 10 rats were survived in each group. At 1 week and 3 weeks after intervention, left ventricular end-diastolic diameter (LVEDd) and left ventricular end-systolic dimension (LVESd) in model group were significantly higher than those in control group, and left ventricular ejection fraction (LVEF) in model group was significantly lower than that in control group (P＜0.05); LVEDd and LVESd in intervention group were significantly lower than those in model group, and LVEF was significantly higher in intervention group than that in model group (P＜0.05). At 1 week after intervention, serum creatine kinase isoenzyme MB (CK-MB), cardiac troponin I (cTnI) and cardiac troponin T (cTnT) contents in model group were significantly higher than those in control group (P＜0.05); Serum CK-MB, cTnI, cTnT contents in intervention group were significantly lower than those in model group (P＜0.05). At 3 weeks after intervention, serum cTnI and cTnT contents in model group were significantly higher than those in control group (P＜0.05); Serum cTnI and cTnT contents in intervention group were significantly lower than those in model group (P＜0.05). At 1 week and 3 weeks after intervention, serum malondialdehyde (MDA) contents in model group was significantly higher than that in control group, and serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) contents were significantly lower than those in control group (P＜0.05); Serum MDA contents in intervention group was significantly lower than that in model group, and serum SOD and GSH-Px contents were significantly higher than those in model group (P＜0.05). Conclusion Ligustrazine injection can reduce myocardial cells injury and oxidative stress reaction and improve cardiac function in AMI rats.