Abstract: This problem with respect to the younger generation requires priority attention, as the adoption of belated measures dramatically affects the formation of cellular mechanisms of immunity, the state of the endocrine system, and the physical and mental status of the child. The nutritional status and biological diversity of children 3-6 years old with dental caries was assessed in comparison with the diets of healthy children (preschool institutions for children- PI). The diets of children of 4 preschool institutions and 920 families in which children attending preschool institutions live were studied; these objects were investigated in Tashkent city (2 PI), Tashkent and Syrdarya region (1 PI each). 360 layout menus have been studied. It was revealed that the total biological value of diets in practically healthy children in the winter spring season is 67.8 ± 1.4%, in children with dental caries 52.6 ± 1.5%, in the summer-autumn season, respectively 72.2 ± 1.2% and 56.2 ± 1.1. Comparatively high biological value of average daily diets in practically healthy children due to low sugar consumption and high specific gravity of products of high biological value (peas, beans), animal proteins, vegetable fats, PNFA, (polyunsaturated fatty acids) sitosterins, indicates the role biological diversity of diets in the prevention of dental caries.