Cf/LAS composites and TC4 alloy were brazed successfully by vacuum brazing using Ag–Cu–Ti active filler metal. The interfacial microstructure was characterized by a scanning electron microscope, energy dispersive spectrometer and X-ray diffraction. The effects of brazing temperature on the interfacial microstructure and joint properties were investigated in details. Various phases including TiC, TiSi2, Ti3Cu4, Cu (s,s), Ag (s,s), TiCu and Ti2Cu were formed in the brazed joints. Interfacial microstructure varies greatly with the increase of brazing temperature, while the amount of Ti2Cu reduced, but no new phase is generated. The optimal shear strength of the joint is 26.4MPa when brazed at 890°C for 10min. Shear test indicated that the fracture of the brazed joints went through the TiSi2+TiC layer close to the Cf/LAS composites interface.