1. Objectives I investigated the effects and mechanisms of Semen Tiglii(ST, 巴豆), Radix Euphorbiae Kansui(REK, 甘遂) and Pedicelus Melo(PM, 瓜莘) in the view of Sasang Constitutional Medicine. 2. Methods I analyzed the literature about oriental medicine and Sasang Constitutional medicine related to herbal Medicine. The contents analyzed were efficacious disease, dosage, usage, side effect, toxicity. 3. Results The first, similarities of ST, REK and PM are improving Gwangyuk, the Chest Discomfort with Constipation, Dysuria and Nausea, toxic, used in urgency, asministered by itself and used shaped powder. The second, ST and REK used the diseases related water and food metabolism in Soumin and Soyangin. PM used the diseases related Qi and fluid metabolism in Taeumin. The third, diarrhea caused by ST and REK is symptom to retrieve the diseases related water and food metabolism. The vomiting caused by PM is symptom to retrieve the diseases related Qi and fluid metabolism. 4. Conclusions The ST, REK and PM is good herbal medicine (() retrieve the urgency symptom caused by the body unbalance in Sasang Constitutional Medicine. The proper dosage is essential because of toxicity of drugs.