1. Objectives: The purpose of this study is to find the association between personality pattern and quality of life according to Sasang Constitution. 2. Methods: The 529 subjects whose constitutions had been confirmed by the experts on the base of drug response were recruited. Personality questionnaire was composed of 15 personal characteristics items measuring the influence of yin/yang and health estimating instrument was SF-12 evaluating the quality of life. Two-way ANOVA was conducted to analyze the Sasang Constitutional difference according to personality pattern. 3. Results: There were 5 different items in PCS(physical component summary), 7 different items in MCS(mental component summary). The individual scores of 3 items - give up easily/stand, decide easily/hard and be exited easily/rationalwere different according to the Sasang Constitution. 4. Conclusions: We suggest that psychological factors may affect the health state, especially might affect the health state of Sasang Constitution differently.