Abstract: The process of interfacial reaction in SiC filament/titanium matrix comsposites and the morphology of the reaction zone were investigated by the use of phase diagram and diffusion path theory.The diffusion path of SiC/Ti interfacial reaction is affected directly by the surface condition of SiC filawent.Coating SiC filament with TiC,or coating it with carboa-base coatings to form Ti₃SiC₂ layer ca its surface at the initial stage of reaction,can effectively control the interfacial reaction and therefore protect the filament from reaction.The layer sequence in the interfacial reaction zone is not necessarily in agreement with the phase sequence in diffusion path.