Introduction and Hypothesis: We have reported that the thickness of epicardial adipose tissue (EAT) by echocardiography related to unstable presentation of coronary artery disease. The aim of this study is to assess the relationship of EAT and plaque vulnerability using analysis of plaque components by virtual histology intravascular ultrasound (VH-IVUS). Methods: We consecutively enrolled 60 patients (41 males, 59짹9 year-old), who underwent coronary angiography and VH-IVUS. EAT by echocardiography was measured on free wall of the right ventricle at end diastole in the parasternal window. All patients were divided into EAT���3mm (thick group, n=21) and <3mm (thin group, n=39). VH-IVUS examination of all 3 coronary arteries was performed. VH-IVUS analyses were reported in absolute area and percentages of each plaque (fibrotic (FI), fibrofatty (FF), dense calcium (DC) and necrotic core (NC)). And plaque burden was also analyzed. The numbers of total thin-cap fibroatheromas (TCFA) of 3 vessels were calculated. These VH-IVUS parameters were compared according to the EAT. Results: The result of VH-IVUS parameters according to EAT are listed in Table. VH-IVUS volumetric analysis showed that thick EAT group had more plaque burden and TCFA, and larger NC and DC total absolute areas than thin EAT group. Conclusion: This study implies more vulnerable plaque in thick EAT group. The increased plaque vulnerability of the patients with thick EAT might be related to the unstable presentation of coronary artery disease.