Objectives : This study aim to find out the reason why perspiration related with the Heart in Korean Medicine. Results : Perspiration is closely connected with the Heart because sweat is a kind of ultrafiltrate of the blood and the Heart conducts blood. In order to perspire, it is necessary to increase blood flow to capillary surrounding sweat glands. The Heart plays an important role in increasing blood flow to capillary surrounding sweat glands. Perspiration controls the body temperature. It must be increase the blood flow to skin in order that down the high body temperature. The Heart plays an important role in increasing blood flow. Conclusions : Perspiration is closely connected with the Heart because sweat is a kind of ultrafiltrate of the blood and there are plenty capillary surround sweat gland. The Heart controls the blood flow to skin in order to regulate of body temperature.