Pathogenesis: hyperkeratosis of the follicular opening, androgen secretion-hyperproduction of sebaceous glands during puberty, action of bacteria, fungi, mites. Grade Ⅲ: Mild Grade Ⅰ: Acne only, individual inflammatory papules. Moderate Grade II: In addition to pimples, there are many inflammatory papules and individual pustules. Grade III: In addition to inflammatory papules, many pustules, individual nodules, cysts involving only the face. Severe Grade IV: In addition to pustules and papules, there are many nodules and cysts involving other areas such as the trunk. Treatment: The general principle is to keep the area clean, not to consume spicy and stimulating oily food, to ensure sufficient sleep and to eat more fruits. Treatment is based on anti-keratinization, anti-infection, anti-androgen and inhibition of sebum secretion. Mild cases can be treated by topical application alone. Moderate sometimes need oral antibiotics or herbal treatment. Severe mostly need to add retinoids or anti-androgen treatment.