The control problem for task-space bilateral teleoperation system with uncertain kinematics and dynamics is studied in this paper. We first demonstrate that based on the proposed controller and adaptive laws, the teleoperation system is stable and the position tracking in the task space is guaranteed when robots are in free motion or subject to passive force. Furthermore, if the human and environmental forces are bounded and square integrable, then all signals of the teleoperation system are bounded and the task-space tracking errors converge to zero asymptotically. The force reflection of the addressed bilateral teleoperation and the issue of communication delays are also studied in this paper. Numerical simulations are presented to validate the performance of the developed control algorithms.