Abstract: The Influences of chemical composition and heat treatment parameters including temperature,cooling rate for quenching and teimpering on the mechanical properties of 1Cr10Mo1NiWVNbN rotor steel were investigated by means of tensile and impact tests,as well as optical microstructure analysis.The results show that the contents of carbon and nitrogen should be controlled at the lower intermediate level,the contents of vanadium and niobium upper intermediate level,the contents of nickel and manganese at the upper limit,and the content of chromium at the lower limit in order to obtain the better mechanical properties.The strength of the tested steel increased continuously and the impact toughness decreased with the raising of quenching temperature.With the raising of second tempering temperature,the strength decreased,and both the ductility and impact toughness increasd,and the second tempering temperature should be higher than 690 ℃ in order to satisfy the specification of steel.With the decrease of cooling rate for quenching ,the strength and ductility as well as toughness decreased.With the decrease of cooling rate for tempering,the strength increased and the impact toughness decreased.