In this paper, in order to improve the control performance and increase the efficiency of Vestas 660 kW wind turbine, a research based on theory and practice, using real data is done, and a state feedback controller is designed. The actual data obtained from Binalood wind power plant, show that these turbines have a low efficiency. This is due to the poor performance of the classical controller in tracking maximum power in the partial load area, and the significant error in measurement of wind speed. In this research, to solve these problems, a state feedback controller is designed which improves the turbine performance. In this controller, in order to control the generator torque, feedback of generator speed and aerodynamic torque are taken. Also, using the rotor speed and aerodynamic torque, the wind speed is estimated much more accurately than it is measured by an anemometer. Since, an accurate model of the system is needed for controller design and simulation, wind turbine modeling is done in different subsystems, and its parameters are identified using real data. Simulations performed in MATLAB, indicate the improvement of the system performance with the designed state feedback controller, compared to the classical controller in the actual wind turbine