The black marks on the legs are pigmentation, which can be treated with topical medication, systemic medication, laser and intense pulse light. 1. Topical drug treatment: using decolorizing agents such as 4% tretinoin, 2%~5% hydroquinone cream, 15%~20% azelaic acid cream and compound arbutin cream can inhibit tyrosinase activity to reduce pigment. In addition, retinoic acid can affect melanin metabolism and reduce melanin production. Chemical stripping with fruit acid and adding decolorizing agent can achieve good results. 2. Systemic medication: oral vitamin C, vitamin E and tranexamic acid can lighten the pigmentation. In severe cases, large doses of vitamin C can be injected intravenously. 3. Laser or intense pulsed light treatment: Q-switched large spot low-energy laser and intense pulsed light irradiation are also effective in reducing pigmentation. If you need to remove the black marks on your legs, do not use drugs on your own, you need to seek medical treatment as soon as possible to avoid serious complications.