OBJECTIVE To observe the preventive effect of xinmaikang capsule against acute myocardial ischemia in coronary artery occlusion dogs. METHODS 25 healthy hybrids dogs, male and female, were randomly divided into control group (physiological saline solution), 40 mg/kg Di'aoxinxuekang Group, xinmaikang low doses (1.55 g/kg), median doses (3.10 g/kg) and high doses (6.20 g/kg) group, 5 dogs a group. The left downwards coronary arteries of dogs were ligated to establish the acute myocardial ischemia model. The blood gas analysis, myocardial enzyme detection, blood pressure,heart rate and epicardial electrogram recorded were detected before and after the stomach lavage. 240 min later, the myocardial tissues were stained with NBT technology to examine the sizes of infarction areas. RESULTS (1) Each dose of xinmaikang capsule could increase coronary artery blood flow (CBF) and reduce the coronary resistance (CVR) (P < 0.05 or P < 0.01). (2) The median and high doses of xinmaikang capsule could decrease myocardial oxygen consumption significantly (P < 0.05 or P < 0.01); (3) In the median and high doses of the xinmaikang capsule groups, the infarction areas decreased significantly (P < 0.01). (4) Serum lactate dehydrogenase (LDH) and Creatine phosphokinase (CPK) levels decreased significantly (P < 0.05 or P < 0.01) in all xinmaikang groups. CONCLUSIONS Xinmaikang capsule has the effect of anti-myocardial ischemia and can protect myocardial cells, which is a potential drug and precaution treatment for myocardial ischemia.