Background: Intra-Vascular-Ultra-Sonography (IVUS) is useful to identify plaque burden in coronary artery. Recently, attempt to characterize plaque nature has been performed. One of them is Virtual Histology. However, Accuracy or usefulness of Virtual Histology was not evaluated yet in Korea. Method: All patients (61.3짹11.3 year-old, male:female=24:39) with coronary artery disease, in whose procedure Virtual Histology was performed from Feb 2006 to June 2006, are evaluated retrospectively. Clinical data, angiographic finding, IVUS finding, Virtual Histology finding were analyzed in all patients. Result: Stable angina pectoris, unstable angina pectoris, and acute myocardial infarction was in 9, 40, and 14 patients respectively. Target lesions were LAD in 32(50.8%), LCX in 3(4.8%), RCA in 22(34.9%), LMS in 6(9.5%) patients. Twenty patients had TIMI flow less than III. Fibrous, fatty fibrous, necrotic core, and calcium distribution was not different in different disease entity(62.60%, 19.95%, 14.38%, 3.07% in stable angina pectoris, 66.07%, 16.27%, 13.10%, 4.56% in unstable angina pectoris, 66.88%, 20.41%, 9.50%, 3.21% in acute myocardial infarction, respectively, p>0.05). Fatty fibrous area had negative correlation with the level of modified LDL cholesterol(r=-0.974, p=0.026). We obtained the more angiographical acute-gain in patients with more fibrous plaque(r=0.323, p=0.045). Stent deployment was done in 61 patients. Stent diameter was 3.49짹0.53mm. Stent length was 25.0짹6.2mm. Success rate of intervention was 96.8%. Target lesion revascularization developed in one patient. His necrotic core percentage(25.7%) was higher than mean (12.3짹11.4%). Conclusion: Successful percutaneous coronary intervention could be performed with aids of Virtual Histology. More angiographic acute gain in intervention was expected in patients with more fibrous plaque. Fatty fibrous plaque burden via Virtual Histology was associated with the level of modified LDL cholesterol.