The ankles are blackened by friction with shoes, keratin abrasion, darker skin, etc. You can replace the shoes, use whitening products, and so on. 1. Shoe friction: shoes and skin friction leads to local melanin deposition, you can change shoes can be solved. 2. Keratin abrasion: the ankle area of long-term wear and tear caused by the local skin over-keratinization, thus becoming harder, but also black. This can only be improved by wearing comfortable shoes. 3. Darker skin: congenital causes or later do not pay attention to sunscreen, you can use whitening products to cover, usually pay attention to sunscreen and so on. Ankle grinding black if necessary can go to the hospital to consult the doctor, under the guidance of the doctor to give the appropriate treatment.