Abstract: The effects of 150℃ aging on the shearing strength and fracture surface characteristics of Sn-0.7Cu-xSb/Cu (x=0,0.25,0.5,0.75,1.0) soldering joints were studied by scanning electron microscopy and energy dispersive X-ray spectrometry. The results indicate that the shearing strength of the joint increases with the increasing of Sb in solder and reduces remarkably with the increasing of aging time. The location of fracture is at the solder and appears at interface between the solder and the intermetallic compound of Cu₆Sn₅. Fracture for post-soldering specimen with a lot of dimples on its surfaces occurs mainly at the solder,and the fracture type is ductile. With the increasing of aging time,the fracture location trends to half solder and half interfacial intermetallic compound. In 500 h aging,Cu₃Sn can be seen at fracture surface which transfers to brittleness from ductileness.