Objectives : The purpose of this study was to investigate the difference of somatization psychological mechanism among Sasang constitution. Methods : Subjects were seventy four students of Won-Kwang university responded the questionnaire. We evaulated the subjects using Minnesota Questionnaire for the Sasang Constitution Classification II(QSCC II), Multiphasic Personality Inventory-2(MMPI-2), 20-item Toronto Alexithymia Scale (TAS-20), Somato-Sensory Amplification Scale(SSAS), Symptom Interpretation Questionnaire(SIQ) and The Ways of Stress Coping Questionnaire(SCQ). Results : From the results of Clinical scale of MMPI-2, the scores of 2nd, 9th, 10th scales was significantly difference. In Lesser Yin group 10th score was the significantly highest of the others, 1st, 3rd, 6th, 7th, 8th score were the highest but not significant. and From the results of PSY-5 scale(The Personality Psychopathology Five scale) of MMPI-2, In Lesser Yin goup, INTR(Introversion/Low Positive Emotion) score was significantly highest, PSYC(psychoticism), NEGE (Negative Emotionality/Neuroticism) was higher than the others. In TAS-20K, SSAS, SIQ and SCQ Lesser Yin group was not significantly difference. but Lesser Yin group had the tendency of difficulty describing feelings and externally oriented thinking and higher score in physical and psychological interpretation. We observed generally lower levels of stress coping strategy scores than the others. Conclusions : These results showed that Lesser Yin group tend to somatization compared other constitution.