In situ synthesized TiB reinforced titanium matrix composites of Ti-B and Ti-TiB2 systems have been prepared by spark plasma sintering at 800-1200 °C under 20 MPa for 5 min. The effects of sintering temperature and reinforcement volume fraction on flexural strength, Young’s modulus and fracture toughness of the composites were investigated. The in situ synthesized TiB reinforcements are randomly and uniformly distributed in titanium matrix. The TiB whiskers are aligned along  direction, and the crystallographic planes of the TiB needles are always of the type (100), (101) and (10 1) . The parallel TiB were observed in β-Ti grains in both of the investigated composites. The in situ TiB needle is likely to grow along  direction which is parallel to  direction of cubic lattice of β-Ti phase.