High energy ball milling was successfully applied for the mechanosynthesis of MgO + TiC nanocomposites by means of the magnesiothermic reduction in the Mg/TiO2/C system. The results of this research work can be summarized as follows:1–According to the amount of Mg in the TiO2 + Mg + C mixture, the reactions can be divided into the following groups resulting in different behaviors:(A)Stoichiometric Mg content (Mg = 2 mol), the MSR mode reaction and whole amount of carbon used to carbide formation. The titanium carbide mg115 would be suggested as TiC0.76 after 20 h of milling and no by-product was observed.(B)Under-stoichiometric Mg content (0.5 ≤ Mg < 2 mol), the magnesiothermic reaction occurred in MSR mode and activated the carbothermal reaction in the sample with 1.5 mol Mg. The formation of MgTiO3 as a by-product was observed specially in the sample with 0.5 and 1 mol Mg.(C)Over-stoichiometric Mg content (2 < Mg ≤ 2.4 mol), the magnesiothermic reaction occurred in MSR mode in the sample with 2.2 mol Mg, while in the sample with 2.4 mol Mg, the magnesiothermic reaction gradually took place and large amounts of Mg2TiO4 and MgTiO3 were formed as by-products.2–The SEM micrographs of the sample with stoichiometric ratio illustrated embryo sac after 20 h of milling, the average particle size distribution was narrow, and got homogenized in size. By increasing the milling time to 60 h, the powder particles adhered together and made large agglomerations.