Rotor, a key component of steam turbine, has a tendency of thermal embrittlement after long-running. The severity of thermal embrittlement must be monitored timely to correct some process parameters such as warm-up time and so on to avoid further damagement. Compared with conventional destructive methods (e.g. small punch test), nondestructive approaches (e.g. chemical corrosion and electrochemical method)has drawn significant attention in predicting the material degradation in turbine rotor steels without impairing the integrity of the components. In this paper, the principle and characteristics of the nondestructive methods for predicting the temper embrittlement of turbine rotor steel were reviewed.