Objectives: The purpose of this study was to examine the psychological factors of Sasang constitutions which are classified by QSCC II(Questionnaire for Sasang Constitution Classification II) using major personality tests which are based on western psychological theory. Methods: 151 college students completed the MMPI-2, MBTI, NEO-PI-R, TCI-RS, and QSCC II. The data were analyzed by ANOVA and post hoc testing to find which personality scale significantly differentiated each Sasang constitution style. Results: MMPI-2, scale 2(D), 5(Mf), 7(Pt), 0(Si) and introversion scale(INTR) showed significant differences between Soeumin and Soyangin. Also, on the dimension of introversion-extraversion in MBTI, and neuroticism(N) and extraversion(E) in NEO-PI-R, there were differences between Soeumin and the other two constitutions(Soyangin and Taeeumin). Finally, in TCI-RS, there were differences between Soeumin and Soyangin on the scale of novelty seeking(NS) and reward dependence(RD), and with regards to the harm avoidance scale(HA), Soeumin received a higher score than any other constitutions. Conclusions: The analysis demonstrates that the classification of QSCC II is most consistent between Soeumin and Soyangin across 4 major personality tests.