In this paper, to improve operability of the operator, we developed the 3D visual feedback system for Cybernic master system. This Cybernic master system is a master-slave system for manipulations and consists of master-slave robot arm and visual feedback system. To reap full advantage of the system, not only feedback to somatosensory system such as force and impedance control but also optimal visual feedback is an important factor in transmitting information to an operator. To achieve visual feedback, it is installed stereoscopic vision and operation assist system using Augmented Reality. The stereoscopic vision is controlled by our active control method of a convergence angle depending on the distance to objects. The operation assist system can show stereoscopic images that is overlaid the virtual objects. We conducted experiments to verify that the operator can view parallax image stereoscopically at the leaching range that is near to an arm. Our system in short distance was effective compared with normal parallax method. Then, we conducted operation test to ensure that it is possible to perform the area protection with the virtual object. At the result, protection areas were formed, and we ensured that slave arm could not invade those areas. In addition, the operation assists such as not only protection of crash but also the tracing movement and operation instruction by the virtual objects is possible. To achieve the interaction between the object of the virtual space and an object of the reality space has improved the operability of the master-slave system.