Black marks on the skin may be caused by heredity, friction and other physiological factors, or considered to be caused by acanthosis nigricans, post-inflammatory hyperpigmentation and other diseases, which need to be removed by general treatment, medication, physical therapy and other ways to deal with the cause of the disease. 1. Physiological factors: Black marks on the skin caused by heredity, friction and other physiological factors, generally do not need to take special treatment measures. For those who have cosmetic needs, laser treatment can be taken to help remove black mark melanin. 2. Acanthosis nigricans: black marks on the skin melanin may also be caused by acanthosis nigricans, the patient can follow the doctor’s instructions for external use of Vitamin A drugs, such as Vitamin A acid gel, Vitamin A acid cream, etc., and the local lesions can be taken to laser, electrocautery, etc., which is conducive to the removal of melanin pigmentation on the skin. 3. Post-inflammatory hyperpigmentation: black marks on the skin melanin is also considered to be caused by post-inflammatory hyperpigmentation, the patient can follow the doctor’s instructions to inhibit the proliferation of melanocytes class of drugs, such as hydroquinone cream, hydroquinone, or vinpocetine class of drugs, such as vinpocetine cream, adapalene gel and so on. Or take laser treatment, after standardized treatment, can play a role in removing black marks melanin. There are many causes of black mark melanin on the skin, and patients are advised to identify the causes.