A rotor for an electric rotating machine includes a rotor core and a plurality of magnetic poles. The rotor core is formed of a plurality of magnetic steel sheets laminated in the axial direction of the rotor core. The magnetic poles are formed on a radially outer periphery of the rotor core. The magnetic poles are arranged at predetermined intervals in the circumferential direction of the rotor core so that the polarities of the magnetic poles alternate between north and south in the circumferential direction. Furthermore, the magnetic steel sheets forming the rotor core are welded so that a plurality of welds are formed on one of radially outer and inner surfaces of the rotor core. Each of the welds has a pair of axial end portions that are offset from each other in the circumferential direction of the rotor core and electrically connected to each other.