Background: The early assessment of cardiac risk is import ant in patient s with unstable angina (UA). The present study investigates the prognostic value capacities of cardiac specific troponin T (cTnT ), cardiac specific troponin I (cTnI) and ECG change in Korean patient s with UA. Methods: Two hundred thirty patients (61 ±11 year , male:female=172:58) admitted to Chonnam National University Hospital via emergency room under the diagnosis of UA and underwent diagnostic coronary angiography (CAG) between July 1998 and June 1999, were analyzed according to the ECG findings of ST depression (STD), T wave inversion (TWI), cTnT and cTnI. Clinical characteristics, initial and follow-up CAG findings, and major adverse cardiac events (MACE) within one year were compared. Results: Among the enrolled patients, 164 (71.3%) patients had significant coronary artery stenosis (CAS). During the one-year follow-up period, 40 patients developed MACE: 2 patients died, 7 patients had acute myocardial infarction and 34 patients developed restenosis. Positivity of cTnT and cTnI was associated with presence of CAS (p <0.001) and multi- vessel diseases (p <0.001). Levels of cTnT (5.7±8.4 vs 1.6±3.1 mg/ Dl, p <0.001) and cTnI (0.11±0.18 vs 0.03 ±0.19 mg/ Dl, p <0.001) were associated with MACE. The presence of STD was associated with the presence of CAS (p <0.001), multi-vessel diseases (p <0.001), low Thrombolysis In Myocardial Infarction (TIMI) flow (p <0.01), ACC/ AHA types (p <0.001) and MACE (p <0.05). TWI was associated with TIMI flow (p <0.05), ACC/ AHA types (p <0.001). In the patients with negative cTnT or cTnI, the negativepredictive value of MACE within 1 year was 87.1% and 93.4%, respectively. In the absence of STD, that of MACE within 1 year was 87.1%. Conclusion: The level of troponin and electrocardiograhic findings are valuable in the early stratification of cardiac risks in Korean patients with UA and the prediction of MACE.(Korean J Med 61:506- 517, 2001)