This article presents an adaptive control scheme based on position-force architecture to achieve the stability and transparency for teleoperation in unknown or varying environments. Without any knowledge about the parameters of the slave robot and environment dynamics, the proposed scheme guarantees the robustness to the parameter uncertainties of the master robot as well as the stability of the whole teleoperation system. Numerical simulations are presented to demonstrate the transparency and robustness to the parameter uncertainties of the master robot. Experimental results to a master-slave system show the validity of the proposed scheme. (C) 1998 John Wiley & Sons, Inc.