In this paper, a new robust control law is presented for robot manipulators subjected to uncertainties. Stability of the system is established by the Lyapunov function, and a control law that guaranteed the system stability is derived as a result of analytical solution. Apart from previous studies, uncertainty bound is determined with the estimation law to control the system properly and the estimation law is written as an exponential function of robot kinematics, inertia parameters and tracking error. Due to asymptotic stability and increasing convergence rate, tracking performance for the case of transient and steady-state are increased. (C) 2003 Elsevier B.V. All rights reserved.