The two sides of the chin are dark and black, considering that it is caused by post-inflammatory hyperpigmentation, liver disease, melanosis, immune diseases, etc., and it can be improved by medication and laser treatment. 1. Post-inflammatory hyperpigmentation: mostly secondary to eczema dermatitis and other inflammatory skin diseases after healing, due to the onset of inflammatory substances to stimulate melanocytes to produce too much melanin. Generally can be self-recovery, but can use hydroquinone cream, vitamin C, etc. to accelerate the recovery, or directly using cosmetic laser to improve hyperpigmentation. 2. Liver disease: chronic cirrhosis patients will affect the blood circulation, making the body toxin stagnation can not be discharged smoothly, resulting in a grayish yellowish black color, lack of luster, at this time it is necessary to target the underlying diseases for treatment, a reasonable diet, including a light diet, eat more fruits, reduce the burden on the liver. 3. Melanosis: also known as melanosis, mostly in the face and neck of the diffuse hyperpigmentation, etiology and pathogenesis is not clear, mostly considered to be the use of poor-quality cosmetics caused by the treatment to avoid the use of poor-quality cosmetics, supplementation of vitamin C in the right amount, or to take the way of cosmetic laser to improve. 4. Immune system diseases: such as scleroderma, skin degeneration, thickening and fibrosis as the characteristics of connective tissue disease, this disease can cause multi-system damage, in which the skin damage can be caused by black, treatment can be considered immunosuppressive drugs such as methotrexate. The darkness on both sides of the chin, need to actively consult the doctor, clear cause for targeted treatment. The above drugs should be used in accordance with medical advice.