A wind power generation system capable of outputting generated power at high efficiency with a smoothed output power includes a wind power generator and a laser aerovane mounted on the wind power generator or located near the wind power generator. Direction and velocity of wind blowing toward the wind power generator are observed using the laser aerovane, and a yaw angle and/or a pitch angle of the wind power generator is predicted and controlled based on the observation results. Thus, high-efficiency control of the wind power generation system, including the wind power generator, is achieved. An output-smoothing device connected to the wind power generator predicts and controls electric power input/output of the output-smoothing device based on a predicted power output of the wind power generator and smoothes the power output of the wind power generation system.