It has been many years to diagnose acute myocardial infarction （AMI） by evaluating the activity of serum enzymes such as asartate aminotransferase （AST）, lactate dehydrogenase （LD）, creatine kinase （CK） and their isoenzymes. In recent year, some protein markers, such as CK-MB mass, myoglobin, troponinT and troponin I have been used in clinical diagnosis. Myoglobin is a good marker to rule out AMI because of its high negative predictive value (NPV), troponin is a good marker to confirm diagnosis because of its high clinical specificity. The analysis property is better than that of CK-MB. Protein markers can be used to do risk stratification and monitor treatment as well. Due to the low price of analysis, serum enzymes are still effective markers for assistance of AMI diagnosis. Sampling time is very important for the evaluation of all these markers.