To provide a turbine rotor with reduced center hole stress that acts on the rotor center hole by changing wheel shape.

This turbine rotor 10 is provided with a wheel 2, which has a wheel portion 2w having a rotor center hole 3, a transition portion 2t formed around the outside periphery of the wheel portion 2w, and a supporting portion 2s with generally constant width that is provided on the outside periphery side of the transition portion 2t. A blade 1 is embedded in and fixed to the supporting portion 2s of the wheel 2. The height of the transition portion 2t is about twice that of the supporting portion 2s. At substantially a center of transition portion 2t, thin-width portion 4 whose width is smaller than that of the supporting portion 2s is formed. Width A of the thin-width portion 4 is about half the size of width B of the supporting portion 2s.