Objectives : This study was carried out to evaluate the difference of body mass index(BMI) distribution and the difference of effect of weight reduction program among Sasang constitution. Methods : Sasang constitution was differentiated by QSCC of 875 cases. Body composition was analysed by bioelectrical impedance Ⅱ analysis(Inbody 3.0, Biospace, Seoul, Korea) in before and after treatment to evaluate the effect among Sasang constitution. The weight reduction program including very low calorie diet, electrical acupuncture and herbal medicine was treated to all cases equally during 1 month. Results and Conclusions : The group of Taeum was more obese and less reducted in body fat mass and % body fat in tools of percent rates of the changes than other type of Sasang constitution. In conclusion, the group of Taeum is more easy to become obese and more difficult to treat obesity.