This research was carried out to examine the correlation between the patients of functional dyspepsia and four constitution (Sasang Constitution). This research examined the correlation of functional dyspepsia versus Sasang Constitution, chronic fatigue, and mental stress in 100 cases of functional dyspepsia. No significant correlation was witnessed between average duration of dyspepsia and gender, and smorking. There was tendency of increased duration of indigestion in relation with length of chronic fatigue and the degree of mental stress. Significant difference was found between the patients with indigestion and Sasang Constitution types. Soeumin among the patients with indigestion were numerous and it was significantly different with normal people. Significant correlation was found between the period of indigestion and chronic fatigue and the degree of mental stress. Significant difference was found between the patients with indigestion and Sasang Constitution types.