Abstract: Taking high purity rare earth yttrium materials, copper and 6061 Al alloy materials as study objects, the soldering and diffusion welding properties of high purity rare earth yttrium targets were studied. The results indicated that the wettability of rare earth yttrium targets to In solder was poor, so it was necessary to metalize the target material to improve its soldering performance. The influence of soldering temperatures on the welding quality of rare earth yttrium targets was studied. The higher the soldering temperature was, the higher the soldering rate of targets was, which was related to the improvement of solder fluidity. The diffusion welding technology of high purity rare-earth yttrium targets and 6061 Al alloy was studied. After the diffusion welding at 400 ℃ welding temperature, 110 MPa welding pressure and 3 h holding time, the diffusion depth was about 8 μm, and the welding interface was metallurgical bonding. The welding strength was up to 70 MPa, which met the high sputtering power requirements of the large size targets of 8～12 inches.