If a mole grows on the body, it is important to understand the classification of moles. Melanocytic nevi are classified as congenital and acquired. If the damage of congenital melanocytic nevus is more than 10 cm in diameter, it is called congenital giant nevus, and those with a diameter of less than 10 cm or smaller than the size of the patient’s hand are called congenital small nevus. Congenital giant nevus has a high rate of malignancy and can occur at any age, so early surgical removal is recommended. Small congenital nevi can also become malignant and need to be followed up closely and surgically removed if there is any sign of malignancy. For acquired nevus, according to the distribution of nevus cells, it can be divided into junctional nevus, mixed nevus and intradermal nevus. For acquired nevus, except for cosmetic requirements, treatment is generally not necessary. For nevus occurring in friction areas such as palm, plantar, and groin, close observation is needed, and if the nevus rapidly expands or breaks down, it should be surgically removed as soon as possible. For patients with cosmetic requirements, if the mole is large, it needs to be removed surgically, and if the mole is small and shallow, it can be treated with carbon dioxide laser. Therefore, for the removal of moles, the treatment methods are not exactly the same depending on the classification.