PURPOSE: To improve operability of a vehicle by not only inputting auxiliary steering but also the difference between the force of the right brake and the force of the left brake so that the behaviors of plane 2 freedom degree may be controlled as aimed.

CONSTITUTION: The desired value of the degree of freedom of the plane 2 of a vehicle according to the running condition including main steering quantity, while the vehicle is in main steering state by means of the steering wheel, is set. In addition, auxiliary steering quantity and the difference between right and left brake force, which are required for realizing the desired value of the behavior of the above plane 2 freedom degree by an auxiliary steering quantity calculation means B and a right and left brake force difference calculation means C are determined by the calculation based on the vehicle characteristics of its own vehicle and equation of motion. At least either the front wheels or rear wheels are auxiliarily steered so as to generate the calculated auxiliary steering quantity in an auxiliary steering means D, and brake is automatically applied to the right and left wheels individually during non-braking and separately during braking so as to generate the calculated difference between the right and left brake in a right and left wheel brake force control means E.