The growth of moles on the body is not necessarily a precursor of cancer, some are ordinary dark pigmented moles, and some characteristic moles need to be alerted to the possibility of malignant changes. Nevus is a relatively common phenomenon, which is a benign skin tumor of melanocyte origin and can occur in any part of the skin. This kind of nevus exists for a long time and does not change in size and nature, and generally does not show conscious symptoms, so it does not need treatment. When some moles appear local itching, burning or pain, rapid increase in size, unclear border, and surface ulcers, peripheral pain, we should be alert to the possibility of malignant transformation, go to the dermatology department of the hospital in a timely manner, there is a tendency to malignant transformation of the person should be excised as soon as possible, and at the same time to do histopathological examination. Surgical excision can be considered for moles occurring in palmar-plantar, waist circumference, armpit, groin and shoulder, etc., which are easy to be rubbed or injured.