The carbothermic reduction and nitridation process of titanomagnetite concentrates with the help of mechanical activation were investigated by particle size analysis, thermodynamic calculation, thermogravimetric analysis, X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive spectroscopy analysis. The thermogravimetric and X-ray diffraction results indicated that either the reduction of iron oxide or the reduction and nitridation of M₃O₅ to TiN could be promoted significantly with the increase in activation time. The results obtained from scanning electron microscopy and energy-dispersive spectroscopy showed that, when samples were not activated, chunks of and thin M₃O₅ were derived from the reduction of ilmenite and titanomagnetite. They were severely sintered with impurities to form a dense structure. As a result, M₃O₅ was difficult to be converted to TiN, especially chunks of M₃O₅. However, when samples were activated, the sintering degrees of the impurity and M₃O₅ were mitigated, and the particle size of the iron as a medium for delivering C to M₃O₅ was decreased in the roasted product. This condition enhanced the diffusion of C to the surface of M₃O₅. Meanwhile, the bulk of ilmenite was broken in the activation process, which prevented the formation of chunks of M₃O₅. Thus, the conversion of M₃O₅ to TiN was promoted