There are three main reasons why we are concerned about moles: 1) fear of malignancy; 2) cosmetic needs; and 3) affecting facial appearance. From a doctor’s point of view, the main thing is to prevent malignant changes. So which moles do we need to pay attention to in order to prevent malignant changes? 1.Congenital pigmented nevus: small (diameter less than 1.5cm), medium (diameter 1.5 – 20cm), and giant (diameter greater than 20cm). The incidence of congenital nevus maligning into melanoma is about 3.8%-18% for congenital giant nevus, and the rate of congenital medium and small nevus maligning is extremely low. 2. Moles in special parts: such as hair covered parts of the head, soles of the feet and toe seams, perineal parts and the back of the body, moles in these parts are not easy to observe, so it is important to consciously check these parts. In addition, Chinese people have more melanomas on the extremities and head and face exposure areas, so for the face and palm and finger (toe) nail areas, we should also keep an eye on them. 3. Moles with special manifestations: such as dysplastic nevus (clark), ink dot-like freckle-like nevus, blue nevus, Spitz nevus, etc. These moles are prone to malignant transformation or have similar performance with malignant melanoma and need to be paid attention to. Halo nevus, due to the attack of melanocytes by autoantibodies, may be a manifestation of fading melanoma in elderly patients and needs to be removed. Eczematous nevi, due to persistent or recurrent inflammation or the appearance of atypical features, are recommended for excision. If the halo disappears after short-term topical hormone application, it may be left unresected. Targeted heme-containing nevi, which are mostly stimulated by trauma, require attention. Recurrent nevi, due to incomplete removal by chemical erosion, freezing or laser, or incomplete surgical excision. Mixed nevi, where several forms of nevi are mixed together, such as blue nevi and congenital pigmented nevi. Capsular nevus, a central hyperpigmented, often nodular, nevus surrounded by an internally depigmented but externally pigmented rim. 4.Moles with the following manifestations: moles with self-conscious symptoms, such as pain, itching and other sensations. Moles that conform to the ABCD principle, A is asymmetrical, B is not smooth edge, C is uneven color, D is a mole with diameter greater than 5mm. There are moles that suddenly increase in size and form nodules, erosions, ulcers and necrosis. 5.People who have melanoma in their family, people who have especially many moles in non-exposed areas, people who had strong sun exposure when they were young, people who are often outdoors, and people who have freckle-like moles that combine with systemic manifestations should pay attention to the moles on their bodies. In addition, moles that appear after the age of 30, especially in the palmoplantar area, should be taken seriously. In conclusion, for patients with melanocytic lesions, it is important to monitor their changes for life, either by whole-body photography or regular dermoscopy. Self-monitoring is important for early detection of melanoma.