The ability of melanin in Chinese sweet gum leaves for scavenging DPPH free radical activity was discussed in order to utilize the resource of Chinese sweet gum leaves. The melanin was extracted by immersion extraction; the crude product of melanin in the leaves was purified with AB-8 macroporous resin. The antioxidant ability of the melanin in the leaves, ascorbic acid (Vc), pyrogallic acid, tert-butyl hydroquinone (TBHQ) and 2,6 Di tert-butyl and other substances was evaluated. The results showed that IC50 value of the melanin crude product prepared by the method was 3.41, the order of scavenging DPPH free radical ability of unit mass of antioxidant was pyrogallic acid>TBHQ>ascorbic acid>Chinese sweet gum leaves melanin crude product>BHT. Chinese sweet gum leaves melanin has a certain ability of scavenging DPPH free radical activity, which, as a natural pigment, has broad application prospect in the field of food, medicine, cosmetics and so on.