Abstract: Due to its great potential value in applications and theory, bilateral tele-robotic systems have been a focus in the literature. Especially, Internet-based teleoperation systems are emerging in recent years, which greatly challenge the control theory to stabilize or control such systems. In this paper, for problems such as stability and transparency, incurred by time-delay of the systems, a review and some necessary analysis on the control theories and methods proposed in recent years are given. Some new ideas about the possible future methods for the control problems of tele-robotic systems are proposed.