The possibility of Mongolian spots on babies is very high, which usually occurs on the buttocks of babies, and can fade away by itself, and some of them may still persist. Mongolian spots occur in the lumbosacral region of infants and young children and are gray-blue spots, which are present at birth and can fade away by themselves after a few years. They are mostly related to genetic factors and are caused by the deep dermis where the melanocytes stay during the embryonic period when they migrate from the neural crest to the epidermis, and have no effect on health. Mongolian spots usually fade away gradually by the age of five, and a few patients may persist into adulthood, especially those with multiple lesions. Mongolian spots will not be malignant, do not need to give treatment, usually there is no special need to pay attention to, no effect on health, do not recommend excessive treatment, observation can be.