A vehicle motion control system is provided. In a first state requiring
understeer suppressing control, a controller determines, based on a yaw
rate deviation, a first control amount of an actuator selected so as to
generate an inward turning moment a vehicle. In a second state requiring
spin suppressing control, the controller determines, based on the
sideways slip angular velocity, a second control amount of an actuator
selected so as to generate an outward turning moment in the vehicle. When
the first and second states are concurrent, the controller selects an
actuator to be controlled by the larger of the absolute values of first
and second cooperative control amounts, and determines a control amount
of the selected actuator as the sum of the first and second cooperative
control amounts. Accordingly, the understeer suppressing control and the
spin suppressing control can be performed in parallel, improving control
performance.