Abstract: The intermediate layer is 1 mm thick TA15 titanium alloy sheet, and the both sides are the 50 mm thick T2 pure copper, diffusion bonding experiments of T2 pure copper and TA15 titanium alloy dissimilar materials were conducted using the vacuum diffusion bonding method. The metallographic microstructure, elemental distribution, fracture morphology of the diffusion bonded interface were observed using scanning electron microscopy(SEM) and electron backscatter diffraction (EBSD). The bonding strength of the interface was tested by uniaxial tensile experiments. The results indicate that the interfacial structures of the diffusion bonded joints obtained under the conditions of 840 ℃-880 ℃, 6 MPa, and 2 h have no obvious defects. The thickness of the diffusion layer increases with the increase of the bonding temperature and holding time. The diffusion layer is primarily composed of Ti-rich solid solution, CuTi2 phase, CuTi phase and Cu-rich solid solution. The grain size is concentrated in the range of 2-15 μm, and the grains are refined and uniform. The Cu/Ti joint prepared at 880 ℃, 6 MPa, and 2 h has the maximum tensile strength of 82 MPa. The tensile fracture mode of the Cu/Ti joint is brittle fracture, and the fracture position is at the CuTi phase region.