SnCu solder is one of the most promising substitutes of SnPb solder, but its creep resistance is worse than that of the other lead-free solders. Particle-reinforcement is a way to improve the creep resistance of solder alloys and cause much more attention than before. A novel Ag particles reinforced SnCu based composite solder is formed and the influence of stress on creep behavior of the composite solder is investigated. Results indicate that the creep resistance of solder joints is superior to that of the SnCu solder joints. Creep rupture lifetime of solder joints decreases gradually with stress increasing. And the creep rupture lifetime of the composite solder joints falls down faster than that of the matrix solder joints. SnCu solder is one of the most promising substitutes of SnPb solder, but its creep resistance is worse than that of the other lead-free solders. Particle-reinforcement is a way to improve the creep resistance of solder alloys and cause much more attention than before . A novel Ag particles reinforced SnCu based composite solder is formed and the influence of stress on creep behavior of the composite solder is investigated. Results that creep resistance of solder joints is superior to that of the SnCu solder joints. Creep rupture lifetime of And the creep rupture lifetime of the composite solder joints falls down faster than that of the matrix solder joints.