1. dry skin (dry skin): the water content of the stratum corneum is less than 10%, pH>6.5, sebum secretion is low, dry skin, lack of oil, fine skin lines, pores are not obvious, after washing the face with a sense of tightness, sensitive to external stimuli, prone to skin cracking, flaking and wrinkles. When cleaning, you can use over fat soap (with a multi-lipid agent soap). 2. Normal skin (normal skin): the ideal type of skin. The water content of the stratum corneum is about 20%, pH 4.5-6.5, sebum secretion is moderate, the skin surface is smooth and tender, not dry, not greasy, elastic, adaptable to external stimuli. Washing can use soft soap (is a potassium soap, the potassium salt of advanced fatty acids, it is softer than the sodium salt of advanced fatty acids, so called soft soap). Liaocheng Fourth People’s Hospital Dermatology Department Wang Dong 3. oily skin (lipid skin): the water content of the stratum corneum is about 20%, pH < 4.5, sebum secretion, the appearance of the skin greasy shiny, large pores, easy to adhere to the dust, skin color is often darker, but good elasticity, not easy to Zou, the general insensitivity to external stimuli. Mostly seen in young and middle-aged and obese people, prone to acne, seborrheic dermatitis and other skin diseases. When cleaning, you can use hard soap (sodium salt of advanced fatty acids. The texture is harder than potassium soap). 4. Mixed skin: is a dry, neutral or oily mixed existence of a skin type. Mostly manifested as the central part of the face (cheeks, nose, nasolabial folds and chin) is oily, while the double cheeks, double temporal areas, etc., as neutral or dry skin. The skin and hair of the trunk are generally the same as those of the head and face. When washing, you should distinguish between oily and dry parts, and focus on oily parts. 5. Sensitive skin (allergic skin): The skin is reactive to external stimuli, sensitive to cold, heat, wind, ultraviolet rays, cosmetics, etc., prone to erythema, papules and itching and other performance. Mostly seen in allergic people.