Abstract: It is a new requirement for the wind turbines to improve the control potential of wind turbines which contributes to the system frequency regulation.The effective utilization of the kinetic energy is not considered by the traditional control methods for the over-speed wind turbines,and the method of selecting controller parameters is insufficient according to the operation status of the wind turbines,which cannot make full use of the frequency control capability for the wind turbine.Thus,an improved frequency control strategy for the over-speed wind turbines is put forward.The kinetic energy from the wind turbines is used to reduce the rate of change of frequency,and the de-loaded power is utilized for primary frequency regulation.The method of selecting the controller parameters is proposed considering the operation status of the wind turbine.The simulation results show that the proposed method can fully use the kinetic energy and de-loaded power to improve the effect of frequency control in the system,and prevent the over-response of the wind turbines,which also ensure stable operation of the wind turbines.