Background: It is not well known which lesions are progressed or regressed in patients with angina pectoris who uses statins. Objectives: We assessed the impact of plaque components on plaque progression in patients with angina pectoris who used 10 mg/d of rosuvastatin using virtual histology-intravascular ultrasound (VH-IVUS). Methods: A total of 66 patients who underwent baseline and 9-month follow-up VH-IVUS for non-intervened intermediate coronary stenosis were grouped according to the plaque progression (increase of plaque plus media area, n=22) or plaque regression (decrease of plaque plus media area, n=44) at the baseline minimum lumen area (MLA) site at follow-up and compared the various parameters including baseline plaque components between both groups. Results: Follow-up low-density lipoprotein (LDL) cholesterol was not significantly different between progression and regression groups (85짹30 vs. 82짹24 mg/dl, p=0.6). Baseline %necrotic core (NC) area was significantly greater (26.1짹10.9% vs. 17.6짹10.8%, p=0.004) and baseline %fibro-fatty (FF) area was significantly smaller (8.1짹6.2% vs. 14.2짹12.1%, p=0.008) at the MLA site in progression group compared with regression group. Thin-cap fibroatheroma was observed more frequently in progression group compared with regression group (32% vs. 9%, p=0.020). The change of plaque plus media area from baseline to follow-up at the MLA site correlated with baseline %NC area (r=0.375, p=0.002), baseline %FF area (r=-0.388, p=0.001), and baseline %FT area (r=-0.242, p=0.050). Baseline %NC area at the MLA site is an independent predictor of plaque progression at follow-up (OR 1.265, 95% CI 1.069-1.497, p=0.006). Conclusion: NC is associated with plaque progression in patients when the LDL cholesterol level is around 80 mg/dl at 9 month follow up in patients with angina pectoris on rosuvastatin 10mg/day.