Biochemical studies have been made on the dynamics of organic matrix of the bone tissue and on its calcification during embryogenesis of chicks. Carbohydrate composition of non-collagen proteins and the degree of mineralization of the bone tissue, as well as utilization of carbohydrates and mineral substances from the egg shell were investigated at various stages of embryonic development. The role of carbohydrates in bone histogenesis and its mineralization is discussed.