Abstract: The strain controlled low cycle fatigue test was conducted on 2CrMo rotor steel at room temperature and high temperatures (450, 500, 566 ℃)and the strain-life relation and cyclically stable stress-strain curves of the steel were obtained. The effect of temperature on the low cycle fatigue property was studied and the fatigue fracture surface was observed. The results show that the cyclic softening phenomena appeared in the tested steel at the experimental temperatures. With the increase of the temperature, the cyclic strength coefficient and cyclic strain hardening exponent of the tested steel decreased; the low cycle fatigue life at the same strain decreased; the distance between the fatigue striations increased and more plastic transformation appeared.