In this paper, we propose a new rotational manipulation by using whole body weight for multi-legged robot. A heavy object can be efficiently moved by putting the robot weight it, and the rotational operation is one of efficient transportation method for big or heavy object. For implementing the operation to the small and light weight robot, the weight-shift control is necessary considering its movable range, balance and actuator power. In the case of rotating the object, the object's balance should be considered. We propose to use Imaginary Zero Moment Point(IZMP) for measuring the balance of the object. When the IZMP is beside the support polygon of the object, the object has rotational force. The rotational force of the object is controlled by external force from the robot, and it can be manipulated by shifting robot's CoM position. The proposed method is implemented to the small multi-legged robot and the effectiveness is confirmed through experiments.