PURPOSE: To make a turn limit point proper at all times and to improve turn performance by changing the setting of a control limit point depending on whether a turn controller is mounted on a vehicle on which the other vehicle turn controller is mounted or not, or depending on whether the other turn controller is operating or not when it is mounted on the vehicle.

CONSTITUTION: A rear wheel steering angle controller ARS and a vehicle behavior stability controller VSC are mounted on a same vehicle. While the controller VSC is operating, a transistor 154 is shut off, current flows into a resistor 142, and voltage of an input terminal 140 of a CPU32 becomes high level, increasing a control limit value. Moreover, when VSC is not operating, the transistor 154 conducts electricity and voltage becomes low level, reducing the control limit value. When the limit value is high, an operation region of ARS is B region, namely, the whole linear region and non-linear region among cornering characteristics, and when the limit value is low, it is only C region and cornering characteristic becomes a turn limit before the nonlinear region to facilitate correction steering.