Abstract For the purpose of controlling motions of a mechanical manipulator in a wide range of work space, an adaptive trajectory control method is proposed. The method can make the manipulator move smoothly regardless of any change of circumstances and track desired trajectories described by arbitrary task-oriented coordinates. The control law consists of a linear feedback and a law of adjusting] gains. Since it requires neither knowledge of parameters of the system nor complicated calculation, it can be easily implemented by a micro-computer. Effectiveness of the method is verified by simulation results. It is shown in particular that an adaptive control law compensating an acceleration term is most effective for fast motions.