Objectives : The purpose of this study is to study the personality traits of Sasang constitutions by comparing the profiles of Temperament and Character Inventory (TCI) and Eysenck Personality Questionnaire (EPQ). Methods : A total of 110 healthy people (20 to 40 years old), except for 2 Taeyangin (TY type), were analyzed; 45 Taeeumin (TE type), 32 Soyangin (SY type), and 31 Soeumin (SE type). A Sasang constitutional medicine specialist diagnosed the Sasang constitution after analyzing the result of a Two Step Questionnaire for Sasang Constitution Diagnosis (TS-QSCD), the external appearance, temperament and symptoms. The dimensions of TCI and EPQ were compared among the different Sasang constitutions, using an analysis of variance, and correlations between TCI and EPQ were analyzed by a Pearson correlation method. Results : Among the four temperament dimensions of TCI, SY type showed a significantly higher score than the SE type in Novelty Seeking. SE type showed significantly higher score than TE and SY type in Harm Avoidance. SY type showed significantly higher score than SE type in Reward Dependence. TE and SY type showed significantly higher score than SE type in Persistence. There were no significant differences in the character dimensions of Self-directness, Cooperativeness and Self-Transcendence. Among the seven dimensions of EPQ, TE and SY type showed significantly higher score than SE type in Extraversion. SE type showed significantly higher score than SY type in Lie. SY type showed significantly higher score than TE and SE type in Impulsiveness. Conclusions : The results demonstrated that there are some significant differences of personality traits among Sasang constitutions. This could help diagnose and understand each Sasang constitution.