Analysis of scientific literature shows a growing interest Mg ions into synthetic calcium phosphate (CaP) biomaterials, especially hydroxyapatite (HAp) formation, as it is established that the presence of Mg ions in HAp biomaterial composition enhances bioactivity of these materials in the body. According to the literature, Mg ions incorporation into HAp structure is limited. Several authors point out different limiting Mg ions concentration incorporated into HAp structure, i.e., in the range 0.3 - 29 weight%. Thus, Mg ions incorporation efficiency depends on the methods of synthesis and Mg ions containing reagent's nature and concentration. The goal - to develop modified HAp synthesis technology for Mg-containing regent adding into synthesis environment, as well as Mg ionsincorporation into the structure of the product and evaluate the effectiveness of inclusion of Mg ions and those impact on characteristics of as-synthesized product and product after thermal treatment. Take the resulting product synthesis phase and molecular composition and morphology studies on the synthesis and heat treatment.