over-steering degree obtaining means for obtaining a value indicating the degree of over-steering in a turning state of the vehicle;

stabilization control executing means for executing vehicle stability control when the value indicating the degree of over-steering exceeds a threshold value, the vehicle stability control applying braking force to at least one predetermined wheel of the vehicle in order to generate a yawing moment in the vehicle in a direction opposite a yawing direction of the vehicle;

specific operation determining means for determining that a specific operation that induces spin tendency of the vehicle has been performed by a driver when the driver has performed a load moving operation that increases a load acting on wheels on the front side of the vehicle body of the vehicle;

specific behavior determining means for determining that a specific behavior representing spin tendency of the vehicle has occurred in the vehicle when the specific behavior determining means has detected a state in which a turning angle of a steerable wheel of the vehicle is becoming smaller due to a steering operation by the driver and yaw rate of the vehicle is maintained to be substantially constant or a state in which the turning angle of the steerable wheel is maintained to be substantially constant due to a steering operation by the driver and the yaw rate of the vehicle is increasing;

storing means for storing the fact that the specific operation is determined to have been performed;

spin tendency determining means for determining that the vehicle is experiencing spin tendency when the specific behavior is determined to have occurred in the vehicle in a state in which the fact that the specific operation is determined to have been performed is stored by the storing means; and

threshold value lowering means for lowering the threshold value when the spin tendency determining means determines that the vehicle is experiencing spin tendency.