Background : There are few evidences explaining positive interrelations of epicardial fat thickness with echocardiographic parameters. The purpose of this study is to investigate the relationships of epicardial fat thickness measured by cardiac computed tomography(CT) with echocardiographic parameters as well as clinical characteristics and severity of coronary artery disease. Subjects and Methods : 186 patients who performed cardiac CT followed by coronary angiography with or without intervention were included, and their epicardial fat thicknesses and main echocardiographic parameters were measured by 2 other investigators. Mean epicardial fat thicknesses were calculated by averaging of 3 epicardial fat thicknesses measured on different sites of right ventricular free wall in short axis view. And their coronary artery disease severity was assessed on the basis of Gensini���s scoring system. Results : Epicardial fat thickness was positively correlated with body mass index (R=0.164, p=0.031), waist-circumference(R=0.316, p=0.002), age (R=0.188, p=0.010), triglyceride (R=0.244, p=0.001), E/A ratio(R=-0.218, p=0.003). But Gensini���s score or hsCRP were not significantly related to epicardial fat thickness. Conclusion : Epicardial fat thickness is positively correlated with E/A ratio, so it can be used by predictors of diastolic dysfunction. But there are no relationships between Epicardial fat thickness and coronary artery disease severity or inflammatory markers in contrast with other studies.