The effect of Pb in copper alloy on the diffusion bondability of copper alloy and ZrO2 ceramic was investigated. The diffusion bonding was carried out at 1173 K for 3.6, 7.2, 14.4 and 21.6 ks under the pressure of 2, 4, 6, 8 and 10 MPa in the vacuum of 1.3 Pa. Microstructure of the bonding interface and the shear fractured surface was researched by SEM and EPMA. The bonding strength was examined with the shear test. The addition of Pb shows the positive effect on the bondability of copper alloy and ZrO2 ceramic. In the joints of Cu-xPb (x=0, 0.5, 1, 2) alloy and ZrO2 ceramic, Pb at the bonding interface releases the thermal stress which was introduced at and near the bonding interface, and it results in the high shear strength of about 50 MPa. The combined addition of Pb and other elements (Ag, Mg, Zn, Al, Ti, Sn and Ni) was not effective on the bondability in all joints.