Hard TiC coating layer is formed on commercially pure titanium by heat treatment in a spark plasma sintering (SPS) mold filled with graphite powder. In case of heat treatment at 1243 K for 3600 s, the obtained thickness of the coating layer is about 10 µm and almost uniform. This coating itself consists of TiC and graphite, and there is no titanium oxide detected by X-ray diffractometer (XRD). Vickers hardness tests have revealed that the hardness of titanium coating is 1600 HV, which is much higher than that of the titanium substrate (130 HV). The hard TiC coating on titanium is considered to be advantageous when applied to load bearing parts of hard tissue replacements. The growth behavior of TiC is parabolic with an activation energy of 218.6 kJ/mol. This value is close to the activation energy of carbon diffusion in TiC. Therefore, the growth rate of TiC is rate-controlled by inward diffusion of carbon in the TiC phase.