Abstract: The experimental investigation on the diffusion bonding of TC4 to ZQSn10-2-3 was carried out in vacuum. CuSn₃Ti₅, Cu₃Ti and rich-Pb layer were formed at the interface zone. The maximum joint strength was 102 MPa. Brittle fracture was explored after shear test, and occurred proximity to ZQSn10-2-3 side. Using copper as the interlayer, element Sn and Pb can be avoid diffusing from ZQSn10-2-3 to TC4. Then there were little CuSn₃Ti₅ in the interface. Fracture had certain plasticity, and the maximum strength of joint was 196 MPa. The optimum bonding parameters were:bonding temperature T=830℃, bonding pressure p=10 MPa and bonding time t=30 min.