To increase the surface hardness of titanium (Ti), the boride layers composed of TiB 2 and TiB, were prepared on the CP-Ti substrate by spark plasma sintering (SPS) technique with micro-TiB 2 powders as boride source. Effects of sintering temperature and holding time on the microstructure, thickness, growth kinetic and hardness of boride layers were investigated. Experimental results showed that the boride layers were composed of a continuous TiB 2 top-layer and a TiB nano-whisker sub-layer. The maximum thickness of boride layers of TiB 2 and TiB were 2.24 ± 0.49 μm and 15.63 ± 6.97 μm, respectively. The activation energy of boron atom for the SPS boride process was calculated to be 386.49 kJmol −1 for the TiB 2 layer and 343.57 kJmol −1 for the TiB layer, which indicates that the SPS can provide enough energy that required in the surface treatment. Boride layers can grow well at a vacuum level of 6 Pa in the SPS. The borided Ti is about six times the hardness of the pure Ti. Boron atoms in the TiB 2 powders were activated by the high temperature and plasma, then reacted with Ti to form TiB nano-whiskers. The holding time of the present method was significantly shorter than other boriding processes. This SPS process provides a new approach for boriding of Ti and its alloys. • Ti boride layer by SPS was composed of TiB 2 and TiB nano-whisker. • The growth of titanium boride layers was enhanced significantly by SPS. • Six times increased hardness of Ti was achieved with short holding time in SPS. • The growth kinetic of boride layers is a diffusion-controlled model.