The aim of the relearn was to study the phase changes during crystallization of some compositions of biocompatible glasses obtained in the RO-CaF2-P2O5-Al2O3-SiO2 (R=Zn, Mg) system. For this purpose, crystallization of glasses in the range of 700-1000 °C was carried out and X-ray analysis was carried out. A change in the phase composition of crystallized glass with a change in crystallization temperature and composition has been established. During crystallization, the phases of whitlockite, zinc-substituted fluorapatite, fluorapatite, anorthite, and gahnite were identified