Objectives: Clinical differences between coronary atheromatous plaques with and without calcium on dual source CT (DSCT) have rarely been studied. We examined clinical meanings of calcified and non-calcified plaques with significant coronary artery disease (>50% diameter stenosis) using DSCT angiography. Methods: From Dec 2007 to May 2008, we studied 102 patients (56 men, 46 women; mean age 64짹9 years) who had chest pain and significant coronary disease detected by DSCT angiography. Patients were divided into two groups: Group Ca, patients with calcified plaques (n=50); Group Non-Ca, patients with non-calcified (lipid or fibrous) plaques (n=52). Results: Patients of Group Ca were older than patients of Group Non-Ca (67짹9 years vs. 62짹9 years, p=0.014). Incidence of major cardiovascular risk factors was not different. Calcified plaques were related to higher calcium score (3928.5 짹 1827.3 vs 28.2짹72.8, p=0.012) and two or more risk factors (p=0.027). Numbers of involved vessels and segments were not different. The composition of clinical diagnosis [acute coronary syndrome (ACS), chronic stable angina (CSA), or atypical chest pain (ACP)] was similar between both groups. However, more patients of Group Ca complained typical chest pain (ACS+CSA) than those of Group Non-Ca (86.0% vs. 55.8%, p=0.001). When Group Non-Ca were subdivided into patients with typical or atypical chest pain, patients with typical chest pain showed higher levels of total cholesterol (198.5짹38.8 mg/dL vs. 174.0짹46.3 mg/dL, p=0.045) and triglyceride (163.7짹74.3 mg/dL vs. 115.5짹53.2 mg/dL, p=0.013) than patients with ACP, although there were no differences of hs-CRP, calcium score, age, sex, or risk factors. Conclusion: Patients with calcified coronary plaques were older, had two or more risk factors, and complained typical chest pain more frequently than patients with non-calcified plaques. Cholesterol and triglyceride levels were higher in patients with non-calcified plaques and typical chest pain than in those with atypical symptoms.