1. Objectives To examine appearances and body shapes is essential of diagnosing Sasang constitution. Although there are many parts and ways to examine appearances, examination of abdomen would be so necessary and important. We focused on angles of costal arch according to Sasang constitution so that we can find some specialty of each constitution. 2. Methods We measured the angles of costal arch of 173 participants who were diagnosed as Sasang constitution after treatments and analyzed by ANOVA and using Scheffe’s t-test or t-test for some independent parameters. 3. Results and Conclusions 81 Taeumin’s mean costal angle is $93.64^{circ}$ to be the widest one. 51 Soyangin have $87.27^{circ}$ mean angle of costal arch to be the second widest one. The next one is Taeyangin’s mean angle of costal arch as $81.66^{circ}$ but the number of them were only 3. The sharpest costal angle which is $71.02^{circ}$ is owned by 38 Soeumin. Male participants have wider costal arch than female in all the constitutional groups.