Abstract: Effects of different transition metals on the diffusion bonding joints of Ti alloy (TC4) to Tin-bronze (ZQSn10-10) were studied.The microstructure of the diffusion bonding joint was analyzed with SEM,EDS and XRD.The results show that when the interlayer was Ni or Ni+ Cu transition metal,Ni could effectively prevent the diffusion between Ti and Cu and thus avoid producing the Cu-Ti intermetallic compounds(Cu3Ti,CuTi etc.),but the Ni-Ti intermetallic compound (NiTi,Ni3Ti) were formed at the TC4/Ni interface resulting in the degradation in the strength of the joints.When the interlayer was Ni,the optimum bonding temperature was 830 ℃ and when the interlayer was Ni+Cu,the optimum bonding temperature was 850 ℃.With the optimum bonding parameters,the tensile strength of joints with Ni interlayer was 155.8 MPa,equal to that with Cu+Ni interlayer and was 65% of the tensile strength of ZQSn10-10 base metal.