1. Objectives Though the distributional rate of Sasangin was mentioned in ${ulcorner}$Dongyi Suse Bowon${lrcorner}$, there were few studies on the distributional rate of Sasangin in Korea. So, this study was conducted to estimate the distributional rate of Sasangin in Korea. 2. Methods The medical records of 1,423 subjects who have taken diagnosis of Sasang constitution from January 2003 to June 2003 at a health examination center of a hospital in Seoul were reviewed. Then distributional rate of Sasang constitution were analyzed and age sex-adjusted standardized distributional rate were estimated by direct standardization using a reference population of 2000 aged from 20 to 70 years. 3. Results and Conclusions (1) The total number of subjects were 1,423(Males : 704(49.5%) / Females : 719(50.5%)). And the mean age of the subjects was $46.3{pm}11.4$ years(males : $45.4{pm}11.3$ / females $47.1{pm}11.4$). (2) Among the 1,423 subjects, distributional rate of Taeumin, Soyangin, and Soeumin were 46.9%, 29.1% and 24.0%(Male : Taeumin 48.2%, Soyangin 37.9%, Soeumin 13.9% / Female: Taeumin 45.6%, Soyangin 20.4%, Soeumin 33.9%). (3) Age sex-adjusted standardized distributional rate of Taeumin, Soyangin, and Soeumin were 45.4%, 28.2% and 26.4%(Male : Taeumin 50.8%, Soyangin 35.1%, Soeumin 14.1% / Female: Taeumin 39.5%, Soyangin 21.0%, Soeumin 39.4%) (4) The rate of Soeumins was higher than that mentioned in ${ulcorner}$Dongyi Suse Bowon${lrcorner}$,and the distributional rate of Sasangin according to sex was different. (5) So it was thought that the distributional rate of Sasangin in Korea was different from that mentioned in ${ulcorner}$Dongyi Suse Bowon${lrcorner}$.