Abstract: The effect of aging treatment at 150℃ for different time on the interfacial microstructure and mechanical properties of Sn-Zn-Ga-Nd soldered joints was investigated. The results show that Ga could suppress the formation of Sn-Nd compound during the aging process and improve the reliability of soldered joints. The mechanical properties of the soldered joints further increased with the addition of Ga and Nd. The shear strength of soldered joints with Sn-Zn-Ga-0.08Nd decreased with increasing aging time,but was still remarkably higher than that of as-soldered joint with Sn-Zn solder.