Vitamin D is an active derivative of fat-soluble steroid, which can promotes the absorption of Ca in the intestine and maintains the concentrations of serum Ca in blood as well as phosphate.Recent researches found that the lack of vitamin D would increase the risk of respiratory diseases, cardiovascular diseases, autoimmune diseases, neuropsychiatric diseases, tumors and other metabolic diseases in addition to affecting the development of bones.More stu-dies have shown that low vitamin D levels is related to respiratory diseases in children.In this review, the physiological characteristics of vitamin D and the relationship with respiratory diseases in children were discussed.