Abstract: The influence of thermal cycling on mechanical properties of the chip resistor joints was studied, which soldered with Sn-Cu-Ni-Ce solder, and the effect of rare earth Ce on mechanical properties of the soldered joints was investigated simultaneously.The results indicate that with the increase of thermal cy cling times, the shear forces of the chip resistor joints soldered with Sn-Cu-Ni-Ce solder decreased gradually, and the reliability of soldered joints decreased as well after long time cycling as a result of the existence of crack in soldered joint.The results also show that the shear forces of the joints increase with the addition of Ce, especially when the content of Ce is at about 0.05%, the mechanical property of soldered joint is better than any other soldered joint before and after thermal cycling.