When a road vehicle makes a turn on a rough road, road disturbance causes fluctuation of vertical load, which results in deteriorated vehicle maneuverability and stability. In the previous study, the authors investigated that the attitude control with additional vertical load control by active suspension was effective to improve vehicle stability in cornering on uneven road surface by using half car model formed from the combination of vertical and lateral motions. In this case, both motions were treated as independent from each other in order to explain the dynamic characteristics. However, considering an actual 4 wheeled vehicle, vertical and lateral motions are not independent due to roll motion. In this paper, by using 4 wheeled full car model which has nine degrees of freedom, the responses of vertical and lateral motions of vehicle body are discussed. And the effect of vertical load control on vehicle stability is verified.