Visual tracking is one of the key components for robots to accomplish a given task in a dynamic environment, especially when independently moving objects are included. This paper proposes an extension of Adaptive Visual Servoing (hereafter, AVS) for unknown moving object tracking. The method utilizes binocular stereo vision, but does not need the knowledge of camera parameters. Only one assumption is that the system need stationary references in the both images by which the system can predict the motion of unknown moving objects. The basic ideas how we extended the AVS method such that it can track unknown moving objects are given and formalized into a new AVS system. The experimental results with proposed control architecture are shown and a discussion is given.