The incidence of malignant melanoma is not high in China, but due to the lack of awareness of its seriousness among doctors and patients, it is usually too late when it is diagnosed, and the treatment results are extremely unsatisfactory. The disease occurs between 30 and 60 years of age. Rarely, the age of juvenile malignant melanoma is 1.5 to 12 years. The younger age group generally has a lower degree of malignancy and a better prognosis after surgical excision. There is almost no difference in gender, but the location of the lesion is related to gender, with males predominating on the trunk and more females than males on the limbs. Pigmented skin lesions with the following changes often suggest the possibility of early malignant melanoma: 1. Color: Most malignant melanomas have brown, black, red, white or blue mixed unevenly. In case of skin nevus with color change, we should be especially vigilant; 2. Edge: It is often uneven and jagged, which is caused by the tumor spreading and expanding to the surrounding area or degenerating on its own; 3. The skin around the lesion may become edematous or lose its original skin luster or turn white or gray; 5.Sensory abnormalities: local itching, burning pain or pressure pain often occur. It is not too much to say that any change of skin mole should be biopsied to remove malignant melanoma.