The mechanical activation was employed to study the phase evolution of the Mg–TiO2–CaHPO4–CaO nanocrystalline system. The powders mixture with certain weight percent was grinded. Thermal annealing process at 650°C, 900°C and 1100°C temperatures resulted in generation of different compounds like MgTiO3/MgO/Hydroxyapatite (HAp) and MgTiO3/MgO/β-TCP and MgTiO3/Mg2TiO4/MgO/β-TCP, respectively. The compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The consequences of XRD analysis revealed that by increasing temperature, some composites with different morphological and structural features were detected. Beside, due to decomposing of HAp around 800°C, HAp converted to whitlockite (β-TCP) with growth of temperature. According to SEM and TEM observations, it was found that the synthesized powder contained large agglomerates which significant content of finer particles and agglomerates with spherical morphology. Because magnesium titanates based dielectric materials are useful for electrical applications, the electrical property of HAp has been proved, and the incorporation of these materials could result in new nanocrystalline dielectric materials.