In a turbine rotor blade of a radial turbine, especially in a variable-geometry turbine with variable nozzles, an object is to restrict high-order resonance of the turbine rotor blade without increasing the size of a device with a simplified structure. A plurality of turbine rotor blades for a radial turbine is disposed on a hub surface. Each turbine rotor blade includes blade-thickness changing portions, at which at least a blade thickness of a cross-sectional shape at a middle portion of a blade height increases rapidly with respect to a blade thickness of a leading-edge side, at a predetermined position from a leading edge along a blade length which follows a gas flow from the leading edge to a trailing edge. The blade thickness increases to a blade thickness via the blade-thickness changing portions.