Luu Hoang with its yellow colour, spongy consistency, sour taste, toxicity, can infultrate inward through the medians of kidney and large bowel. Oral use of Luu Hoang can tossify the “fire”, assiste the “yang”. Topic use can detoxicate, kill the parasite, treat the pimples, Luu Hoang abates the itch in cases of scale, fungi on skin, eczema. Luu Hoang is used in the conditions of boil, the cold in kidney, coldish impaired “yang”, coldish secretion, difficulty in faces exerete and urinate. Oral use of 1-3 g in powder and pill, topic use with powder spreaded in the wound… are the most common methods. Counter indications are in the cases of impaired “iin”, exceeded “fire”, pregnancy, and incompatible with Phac Tieu