This paper presents a novel adaptive bilateral control scheme for obtaining transparency for teleoperation systems that has uncertainties. It has been found that a condition that is equivalent to getting an ideal response in teleoperation is to making the closed-loop dynamics of master and slave manipulators dual. An adaptive approach is applied to achieve the duality for the uncertain master and slave manipulators. Due to the dual closed-loop dynamic characteristics of master/slave teleoperation systems, excellent position and force tracking performance can be obtained without concerning the impedance variation of human and environment. The validity of the theoretical results is verified by experiments with a 1-DOF master/slave system.