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(Ti, Mo)Si₂/MoSi₂ composite coatings were prepared on Mo substrate by the continuous deposition pack cementation method. The X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and thermody-namic calculation were used to characterize the composite coatings and to analyze the formation mechanism. The results show that the co-deposition process cannot achieve the titanium deposition effectively. The titanium-modified MoSi₂ coatings can be prepared by a two-step deposition process of titanizing and siliconizing. The coatings contain three layers: the outer layer is (Ti, Mo)Si₂ ternary compound layer; the second layer is MoSi₂ layer; the layer between the MoSi₂ and Mo substrate is the Mo₅Si₃ transition layer. The siliconizing temperature shows negligible effect on coating structure. The growth rate of titanium-modified MoSi₂ coating is slightly lower than that of single MoSi₂ coating. The growth of (Ti, Mo)Si₂/MoSi₂ composite coating is dominated by the inward diffusion of Ti and Si. Ti is concentrated on the outer layer of the coating. Si diffuses through the (Ti, Mo)Si₂ compound layer and interacts with the substrate to form the MoSi₂ layer and Mo₅Si₃ transition layer. In the titanizing process, the free state AlF₃ is introduced by the reaction among pack mixtures. In the subsequent siliconizing process, a trace amount of Al in free state is precipitated in the form of Al₃Mo phases in the (Ti, Mo)Si₂ layer near the upper interface of MoSi₂ layer. During the cyclic oxidation tests at 1200 °C, the (Ti, Mo)Si₂/MoSi₂ composite coatings do not lose mass obviously after exposure in oxidation atmosphere for 180 h. A dense composite oxide layer consisting of SiO₂ and TiO₂ can be formed by the oxidation of (Ti, Mo)Si₂ phase. This composite oxide layer can fill the surface cracks of the coating and continuously block the oxygen diffusion, so the oxidation resistance of (Ti, Mo)Si₂/MoSi₂ composite coating in the periodic oxidation environment is far superior to that of the single MoSi₂ coating.