The mechanical properties of interfaces in Ti/Al2O3 composites were characterized by four point bending and fiber pushout tests. To determine the bi-material fracture toughness with four point bending tests, planar interfaces were evaluated as sandwich composites. By changing the processing temperature from 700 °C to 1000 °C, the interfacial fracture energy was found to increase up to 950 °C. It then decreases when the processing temperature is further increased to 1000 °C. This is because of the formation of the intermetallic compound (Ti3Al). Interfacial shear strength and interfacial frictional stress of 323 MPa and 312 MPa were obtained, respectively, by performing pushout tests of the Al2O3 fiber reinforced Ti matrix composites. These values are smaller than the shear yielding strength of the Ti matrix which is 525 MPa.