We perform a control study on a three-degree-of-freedom dynamical biped locomotion system. Based on the dynamics of the walking gait and desired joint trajectories, a robust adaptive control scheme consisting of a control law and an application law was chosen. The control law has the structure of the inverse dynamics servo but uses estimates of the dynamics parameters in the computation of torques which propel the biped. The adaptation law uses the tracking error to compute the parameter estimates for the control law. Simulations show that the tracking errors are acceptably small and the performance is robust despite ±25% deviations in the initial parameter estimates.