Objectives: The purpose of this study was to compare the profiles of Junior Temperament and Character Inventory (JTCI) and Sasang constitution in middle school students. Methods: In this study, healthy 89 students(13 to 15 years old) except for 3 Taeyangin were analyzed; 37 Soyangin, 30 Taeeumin, 22 Soeumin. The Sasang Constitutional types were determined by the results of TS-QSCD(Two Step Questionnaire for Sasang Constitution Diagnosis) and the seven dimensions JTCI 12-18(The Junior Temperament and Character Inventory) were compared among the different Sasang types using analysis of variance(ANOVA). Results: In the temperament dimensions, Soyangin showed significantly higher score than Taeeumin and Soeumin in Novelty Seeking(NS). Soeumin showed significantly higher score than Soyangin in Harm Avoidance(HA). Soyangin showed significantly higher score than the others in RD(Reward Dependence) (Soyangin>Soeumin>Taeeumin). In the character dimensions, Soyangin showed significantly higher score than Soeumin in SD(Self-Directness). There were no significant differences in P(Persistence), and C(cooperativeness) and ST(self-transcendence). Conclusions: These results demonstrate that there are some differences of the temperaments and characters among Sasang types and could help adolescents to understand and develope themselves.