Background: Accurate assessment of AV and aortic root is crucial to understand the pathophysiology of abnormalities and management of patient with aortic valve diease. The aim of this study was to evaluate the feasibility of novel semi-automatic assessment of AV and aortic root from volumetric 3-D Echo compared to CT. Methods: Volume-rendered 3-D TEE data were obtained using V5M transducer(Sequoia, Siemens). 6 points (commisures and valve tips) at ED and ES were identified on the 3-D TEE data. Volumetric CT images were acquired using 64-Slice CT. A dynamic 3-D model of the AV and root were obtained by standard mathematical modeling approach. We measured phasic change of the AVA(cm2), diameter of sinotubular junction (d-STJ,mm), sinus of Valsalva(d-SV,mm) and basal ring(d-BR,mm). Results: 8 CT and 3D Echo volume data from normal to mild AR were acquired. 3-D TEE data about AV and root showed strong correlation with CT data(table). Figure showed representative examples of 3-D Echo and CT modeling. Conclusion: This novel automated 3-D Echo approach provides accurate dimensions of the AV and the aortic root and may aid in valve and root repair procedures.