The cause of dark skin in infants may be caused by genetic factors, acquired factors and so on. 1. Genetic factors: dark skin may be caused by genetic factors, such as the baby’s parents skin color are darker, then the genetic probability in terms of skin color is also black, this situation does not require special treatment, is a normal phenomenon. 2. Acquired factors: sun exposure will promote the production of melanin, frequent sun exposure will make the skin darker, this situation does not require special treatment, do a good job of sun protection, reduce the frequency and length of sun exposure, will slowly become more white. The baby’s skin may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.