BACKGROUND and OBJECTIVES Non-ST-elevation MI is a different disease entity from ST-elevation MI. But while undergoing coronary angiography, there are lesions in NSTEMI with TIMI grade 0,1 showing near total occlusion. Our objectives are to get a knowledge in these situations. SUBJECTS and METHODS In 2011, 5694 patients were registered in COREA-AMI (COnvergent REgistry of cAtholic and chonnAm university for AMI) registry. 2324 patients were NSTEMI, and we divided these patients into two groups, based on TIMI flow. Occluded lesion was defined as a lesion with 100% stenosis, or TIMI flow 0,1. 1009 patients had occluded lesion, and 1315 patients had non-occluded lesion. We compared baseline characteristics, ECG findings, in-hospital treatment, and long-term outcomes between patients with and without occluded culprit arteries. RESULTS In baseline characteristics, initial creatine level, peak troponin before PCI, initial ejection fraction in echocardiogrphy, total stent length, follow-up hsCRP showed significant difference between two groups. Also former aspirin, statin, metformin use was different between two groups. Total occlusion in NSTEMI was frequent in left circumflex artery. Using multivariate cox-regression analysis, the hazard ratio for occluded infarct artery was 1.67 (95% confidence interval 1.30-2.70, p=.03). Kaplan-Meier curve for median follow-up of 26months showed a significant difference between occluded and non-occluded lesion group. CONCLUSION In NSTEMI, occluded lesion showed poor outcome than non-occluded lesion. Whether this remains a true hypothesis in STEMI is still a question to solve, and the comparison between totally occluded NSTEMI and STEMI will be studied soon.