Abstract:The incidence of type 2 diabetes mellitus (T2DM) is increasing globally. With the growing prevalence of obesity in childhood, the incidence of T2DM is also on the rise among children. Children with T2DM have worse persistent ability in glycemic control and are more prone to complications than adults. In recent years, some studies have found that vitamin D deficiency is closely related to T2DM in adult patients, and its relationship in children and adolescents has also been reported by more and more studies. In terms of mechanism, vitamin D posses the ability of improving insulin sensitivity and regulating insulin secretion, the former has a relationship with renin angiotensin aldosterone system(RAAS), peroxisome proliferator activated receptor(PPAR), oxidative stress system and other pathways, and later with protein kinase A (PKA), L-type voltage-dependent calcium channel (L-type VDCC), phospholipase C (PLC), ATP sensitive potassium channel（K_ATP）and other signaling molecules. Thus, the review aims to explore the relationship between the deficiency of vitamin D and the incidence of T2DM in children and adolescents and its possible molecular mechanism, so as to provide a reference for the prevention and treatment of T2DM in children and adolescents.