Pigmented moles are the most common benign tumors in the body, referred to as nevi. People of different ages and genders may have nevi. They can exist at birth, most of them appear in the second to sixth year after birth, progress slowly, have no conscious symptoms, and their condition is stable. There are 15 to 20 nevi on the average on the surface of a normal person, and most of them are located in the head, neck and trunk. Naevus pigmentosus is generally divided into intradermal nevus, junctional nevus and mixed nevus. Intradermal nevus is more common, usually protrudes on the surface of the skin, is larger, more round, more black, and may have hair on it, commonly known as nevus. Junctional nevi usually appear at the junction of epidermis and dermis, do not rise above the skin surface when touched, are usually hairless and darker. Generally speaking, pigmented nevus is not harmful to people, due to the different locations of nevus growth, many people think that some moles are good, like eyebrow “mold” in the hidden mole “Zhi”, the chest has a great ambition “mole” and so on, but from the medical science, the mole is not a good choice. “and so on, but from a medical point of view, there are moles or to be vigilant. Like long in the hair, lips, neck back, waist, palms, soles, vulva and other special parts of the pigmented moles need to pay attention to. These areas are prone to friction, which can lead to malignant transformation of the mole into basal cell carcinoma or malignant melanoma. Therefore, it is recommended that moles growing in special areas be removed in a timely manner. This surgery can be done on an outpatient basis. After the surgery, it is best to do a pathologic section of the cut part to observe whether there is any change, whether it has been cut cleanly, and whether it is benign or malignant. However, there is no need to be nervous about all moles, because malignant moles will have some manifestations, such as: new moles appear recently in adults; the original mole has increased significantly in size within 3-6 months; the color has deepened or lightened significantly; the original mole has changed in color or has turned into macular shades, or even loss of pigmentation; the edge of the mole has become irregular or there are satellite-like small moles in the periphery or several moles have merged; Uneven surface; local itching and pain; hair loss in hairy nevus; scabs on the surface of nevus or recurrent inflammation, ulceration, bleeding or ulceration of the nevus; and enlarged lymph nodes adjacent to the nevus. If any of the above manifestations appear, you should pay attention to it and finally go to the plastic surgery department of regular hospital. In addition for the malignant change of color nevus, there are some influencing factors, related to ultraviolet radiation, so you can do some protection, as far as possible to reduce unnecessary sunlight exposure, neck and waist, hands and feet can reduce unnecessary friction stimulation. If you think the mole grows in the face and neck affects the appearance, it can be treated, the diameter >3 mm mole, it is recommended to use shuttle surgery to excise, after excision specimens must be sent for examination. Smaller moles can be treated non-surgically with laser, electrolysis, electrocautery, chemical cauterization and so on.