Melanoma is a common malignant tumor of the skin that is highly dangerous. It is a common skin tumor triggered by excessive proliferation of abnormal melanocytes, which is extremely malignant and accounts for a great proportion of skin tumor deaths. It occurs mostly in the skin or mucous membranes close to the skin, and is also seen in the soft brain and choroid. The incidence varies according to ethnicity, region and race. Is melanoma hereditary? Melanoma multiforme may be related to genetic factors. In a retrospective study of 56 patients with melanoma, risk factors for the disease were analyzed. A total of 157 melanomas occurred in these patients. Of these patients, 64.7 percent had a family history of melanoma and 70.8 percent had a family history of dysplastic nevi. Eighty-two percent of the 50 patients examined had dysplastic nevi. Sixty percent of the patients had a family history of both clinically confirmed dysplastic nevus and melanoma. The mean age of patients diagnosed with melanoma was 38.2 years, and 58.9 percent of patients were younger than 40 years. The mean interval between resection of primary and recurrent melanoma was 34.3 months. In 76.8% of cases, the anatomic site of the recurrent melanoma was different from the initial tumor. The high incidence of dysplastic nevi in patients and their family members, the prevalence of a family history of melanoma, and the early onset of melanoma suggest the involvement of genetic factors in the development of multiple melanomas. Patients with one of these risk factors should therefore take special care. Generally speaking the genetic development of this disease is only one of the factors; the acquired factors are more important. The probability of developing the disease is even higher if the patient’s immediate family members have the disease, combined with adverse external stimuli, such as ultraviolet light.