Series of Titanium boride/titanium (TiB/Ti) composites were fabricated to investigate the relationship between the phase compositions, microstructures and the mechanical properties. Results gave the complete series of properties of the TiB/Ti composites and specially highlighted the effect of excessive Ti fraction, helping the long TiB whisker formation and causing the change of fracture mode of the TiB whisker during the flexural and compressive strength test. According to the fracture modes, the Halpin-Tsai model was used to model the strength of the TiB/Ti composites and results showed a well match between the experimental and calculating strengths, as well as that of the elastic modulus.