This paper proposes a new driver support system which assists driver's operation in an obstacle avoidance scene. The proposed system has actuator systems which are Electric Power Steering (EPS) and Direct Yaw-moment Control (DYC). The obstacle is detected as a differential feature value by using a micro-wave radar instead of a camera. Co-operative control is constructed to manage the actuators by frequency weighting functions. By experiments using an actual vehicle, it is shown that the proposed system has effectiveness for assistance the driver's operation for an avoidance task and for improving vehicle dynamics.