The effects of V particles on the interfacial morphology and tensile properties of Cu/Sn-58Bi-0.4V/Cu composite solder joint during isothermal aging process are studied. The results show that the microstructures of Cu/Sn-58Bi/Cu and Cu/Sn-58Bi-0.4V/Cu joints gradually coarsen,the IMC layers become thicker and the tensile strength of joints reduce with increasing aging time. However,the addition of 0.4%V particles effectively hinders the coarsening of the microstructures,inhibits the growth of IMC,and improves the tensile strength of Cu/Sn-58Bi/Cu joints. Fracture analysis shows that the fracture surfaces of Cu/Sn-58Bi/Cu are brittle. Some dimples on the fracture surfaces of Cu/Sn-58Bi-0.4V/Cu solder joints are observed,showing a certain toughness.