The present study was designed to evaluate the efficiency of total lactate dehydrogenase, total creatine kinase, LD1/LD2 ratio, CK-MB and newly developed troponin T in acute myocardial infarction. The level of troponin T was 0.010.02 pg/L in 34 healthy person, but the peak vaule of acute myocardial infarction ranged in 4.7-24.2 pg/L. Total lactate dehydrogenase was peaked in 1 to 3 days after chest pain and then progressively decreased, but LD1/LD2 ratio was persistently higher than 1.0 for 10 days in most patients. Total creatine kinase and CK-MB were peaked in 1-2 days, and normalized in 3-4 days, so they, were useful in early diagnosis of acute myocardial infarction, but not for the late stages of acute myocardiz l infarction. Troponin T is early elevated and persistently high level for more than 10 days. Comparing with total lactate dehydrogenase, total creatine kinase, LD1/LD2 ratio and CK-MB, troponin-T test improves the efficiency of serodiagnostic method for the detection of ischemic myocardial damage.