Abstract: OBJECTIVE To observe the preventive effects of Ningxin Tongbi capsule on acute myocardial ischemia in dogs. METHOD Thirty dogs were randomly divided into model group(physiological saline solution), Diaoxinxuekang capsule group(20 mg·kg^-1), Ningxin Tongbi capsule low dose, median dose and high dose group, 6 dogs per group. The left downwards coronary arterys of dogs were ligated to establish the acute myocardial ischemia model. Electrocardiogram, some hemodynamic parameters and cardiac oxygen consumption were dectected before and after the stomach lavage. The area of myocardial infarction was determined by NBT immunohisto chemistry. RESULTS Compared with model group, at the dose of 1.02, 2.04 g·kg^-1, Ningxin Tongbi capsule could degrade the S-T migration of electrocardiogram, and increase coronary artery blood flow, CO and LVSP, relieve the infarction areas and levels of serum CK, LDH significantly(P<0.05 or P<0.01). CONCLUSION Ningxin Tongbi capsule has the remarkable protective effects of anti-myocardial ischemia and can protect myocardial cells.