In this work, Ti matrix composite reinforced with dispersed Ti₅Si₃ particles was synthesized via spark plasma sintering starting with Ti and SiO₂. Because reports on the equilibrium phase diagram show that there is a two phase region with O dissolved Ti, Ti(O), and Ti₅Si₃, Ti and small amount of SiO₂ transform into Ti₅Si₃/Ti composite according to a reaction, Ti+SiO₂=Ti(O)+Ti₅Si₃. Initial amount of SiO₂ and sintering temperature were varied in ranges of 2.5–15 mass% and 800–1200°C, respectively. Their dependence on microstructure, bulk density, fraction of spatial occupation and Vickers hardness was studied systematically. From microstructure observation, composition and temperature range to yield Ti₅Si₃/Ti composite was identified. At low temperature sintering, however, SiO₂ remained inside the Ti₅Si₃ envelope, indicating incompleteness of above reaction. A simple analysis was made on the phase transformation mechanism of Ti₅Si₃, supposing that the diffusion of Ti controls this process. Vickers hardness of the Ti₅Si₃/Ti composite increases with increase both in amount of SiO₂ and temperature, but it is remarkably larger than that of commercial pure Ti. The bulk density and fraction of spatial occupation also increases with increase in temperature but decreases with increase in amount of SiO₂. Taking into account the experimental and analytical results, microstructure formation and its effect on the properties are discussed briefly.