Abstract: To provide a flux-cored welding wire and a method for arc overlay welding attaining excellent weldability and low dilution ratio and obtaining a weld bead excellent in corrosion resistance in overlay welding using the flux-cored welding wire having an advantage of high deposition rate and deposition efficiency. The flux-cored welding wire for gas shielded arc welding including flux filled up in an outer sheath and using pure Ar as a shielding gas contains, as percentage to the total mass of the flux-cored welding wire, C: 0.20 mass % or below, Si: 15.00 mass % or below, Mn: 20.00 mass % or below, P: 0.0500 mass % or below, S: 0.0500 mass % or below, and Cr: 15.0-50.0 mass %, with the remainder being Fe and inevitable impurities.