There are many reasons why the skin becomes more and more dull and yellow, and the common reasons are as follows: improper cleansing, skin photoaging, improper use of skincare products, other systemic diseases, etc. Improper cleaning: the accumulation of old keratin on the surface of the skin, as well as dirt, air pollution oxidation of skin secretions, etc. If not removed in a timely manner, in the long run will make the skin become rough and yellowish, loss of luster and elasticity. Skin photoaging: long-term attention to sunscreen, ultraviolet damage to the skin is irreversible, the skin’s ability to resist free radicals weakened, stimulating pigment cells to produce more melanin, and gradually accumulated, manifested as more and more yellowish skin. 3. the use of inappropriate skin care products: when the choice of skin care products and their own skin type is not suitable, the face of the skin can not be fully absorbed in the nutrients in the skin care products, the face of the skin excess nutrients, will lead to facial skin color imbalance in the long term. 4. Diseases of other systems: Diseases of other systems of the body, such as endocrine system diseases, liver diseases, etc., skin dark yellow is one of its clinical manifestations. For progressive dark yellow skin, it is recommended to closely observe one’s own condition and visit a regular medical institution in time to clarify the cause of the disease, so as to avoid delaying the treatment.