Al2O3 Particulate reinforced TiAl based composites have been fabricated by hot press-assisted reaction synthesis (HPRS) method using Ti, Al and TiO2 as starting materials. Effect of the TiO2 addition on the microstructures and mechanical properties of the TiAl/Al2O3 composites were detailedly investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and universal properties tests. The results show that the TiO2 addition has evident effect on phase composition and microstructure of the TiAl intermetallics, as a result, the mechanical properties of TiAl composites are improved. When the TiO2 content is 10.58 wt %, the flexural strength and fracture toughness reach the maximum values of 537.34 MPa and 9.38 MPa·m1/2, which are increased by 70% and 23%, respectively. The strengthening mechanism is also discussed.