Passivity based control, as one of the tools available to design robust controllers, is introducedrnfor trajectory tracking of the Stewart platform. Since Passivity is a fundamental property of manyrnphysical systems which may be roughly defined in terms of energy dissipation andrntransformation, its inherent input output property quantifies and qualifies the energy balance of arnsystem when simulated by external inputs to generate some outputs. PD+ controller is designedrnbased on passivation principle so that the closed loop system becomes globally uniform andrnasymptotically stable.rnThe mathematical model of the Stewart platform, derived from Euler Lagrange equations ofrnmotion, is simulated on MALAB/Simulink with the designed controller. So as to get the desiredrnleg-length trajectory, the inverse kinematics formulation is investigated. The mathematical modelrnis verified using â€œautomatic dynamic analysis of mechanical systemsâ€ (ADAMS) software.rnIn the absence of disturbances, the maximum trajectory tracking error is recorded as ( 0.006m) inrnthe time interval between 0sec and 0.8sec . Applying unit step disturbance makes the errorrn0.006m after 0.8sec , which never be seen in undisturbed system.. The maximum speed of allrnthe six legs trajectory have been found to be 0.43m/ s , 0.49m/ s , 0.48m/ s , 0.5m/ s , 0.5m/ s andrn0.49m/ s respectively. More realistic results are observed from ADAMS simulation results.rnKey words: passivity based control, PD+, global uniform asymptotically stable, Euler Lagrangernequation, ADAMS software, inverse kinematics, MATLAB/Simulink.