Sn-10Sb-5Cu lead-free solder was fabricated for high temperature application in electronic package. Wetting behaviors and interfacial reaction between such a high temperature lead-free solder and Cu substrate were investigated and compared with those of 95Pb-Sn solder. The results showed that the wetting properties of Sn-10Sb-5Cu solder are superior to those of 95Pb-Sn solder in maximum wetting force, wetting time and wetting angle in the temperature range of 340-400 ℃. However, the surface of the Sn-10Sb-5Cu solder sample after wetting balance tests was rougher than that of 95Pb-Sn solder at the temperature lower than 360 ℃. In static liquid-state interfacial reaction, the types and thickness of the intermetallic compounds (IMCs) of both solders were different from each other. The wetting kinetics in the Sn-10Sb-5Cu/Cu system was more rapid than that in 95Pb-Sn/Cu system, and the higher formation rate of IMCs in the former system was considered as the reason. Sn-10Sb-5Cu lead-free solder was fabricated for high temperature application in electronic package. Wetting behaviors and interfacial reaction between such a high temperature lead-free solder and Cu substrates were investigated and compared with those of 95Pb-Sn solder. showed that the wetting properties of Sn-10Sb-5Cu solder are superior to those of 95Pb-Sn solder in maximum wetting force, wetting time and wetting angle in the temperature range of 340-400 ° C. However, the surface of the Sn-10Sb 5 Cu solder sample after wetting balance tests was rougher than that of 95Pb-Sn solder at the temperature lower than 360 ° C. In static liquid-state interfacial reaction, the types and thickness of the intermetallic compounds (IMCs) of both solders were different from each other. The wetting kinetics in the Sn-10Sb-5Cu / Cu system was more rapid than that in 95Pb-Sn / Cu system, and the higher formation rate of IMCs in the former system was considered as the reason.