The present invention provides a solder alloy, a solder paste, a solder ball, a resin flux-cored solder and a solder joint, both of which has the low-melting point to suppress the occurrence of the fusion failure, improves the ductility and the shear strength, and has excellent heat-cycle resistance. The solder alloy comprises an alloy composition composed of 35 to 68 mass % of Bi, 0.1 to 2.0 mass % of Sb, 0.01 to 0.10 mass % of Ni, and a balance of Sn. The alloy composition may contain at least one of Co, Ti, Al and Mn in total amount of 0.1 mass % or less. The solder alloy may be suitably used for a solder paste, a solder ball, a resin flux-cored solder and a solder joint.