Vitamin D is a member of steroid hormone superfamily, in addition to its' classical function, such as regulating calcium and phosphorus metabolism as well as maintaining children's bone health,vitamin D also plays an important role in immune regulation. In recent years, a number of studies have shown that low level of vitamin D is associated with the occurrence and progress of various infectious diseases in children, vitamin D supplementation is used to treat and prevent a variety of infectious diseases in children. In this paper, the relationship between vitamin D nutritional status and infectious diseases in children as well as its anti-infection mechanism are briefly reviewed.