Abstract. Nanostructural changes on initial stages of calcium silicophosphate glasses nucleation in Na 2 О-CаO-ZnO-TiO 2 -ZrO 2 -Al 2 O 3 -B 2 O 3 -P 2 O 5 -SiO 2 system during phase separation have been investigated. It has been established that the presence of drop-shaped nano-and micro-nonuniformities in the structure of calcium silicophosphate glasses substantially affects the glass separation in a precrystallization period, helping intense fine hydroxyapatite crystallization with the crystal size of up to 1 μm after heat treatment.