In an apparatus for actively controlling a steer angle of front wheels of a vehicle in accordance with a steering wheel angle, an active control amount for actively controlling the steer angle of the front wheels is calculated by an equation including a proportional term and a differential term. A coefficient of the differential term is changed in accordance with a lateral acceleration such that it is kept unchanged within a first range in which the cornering power is large, but is increased in a second range in which the cornering power is decreased due to the non-linearity of tires. Thus, the reduction in the cornering power in the second range can be compensated for and the stability and response during the high lateral G turning can be improved.