With the purpose of releasing the effect of the impulse to the robot system and its motion control for the instant the hydraulically actuated leggedrobot touching down with the dynamic gait, a robot′s compliant touchdown control method based on the joint motion planning is presented. Focusing on the hydraulically actuated singlelegged robot as the research object, two ways of robot compliant touchdown is obtained by analyzing the endeffector's impulse, which selects the proper touchdown posture of the robot and reduces the endeffector's velocity before touching down the ground. Furthermore, the joint motion trajectory on both of the flight phase and stance phase are planned. The former is based on the cosine velocity curve and the latter is based on the cosine function curve. Afterwards, the method is applied to the hopping control of the hydraulically actuated singlelegged robot emulated on MATLAB/Simulink and then to the robot prototype. Both of the emulated and experimental results indicate that the pressure impulse in the hip cylinder′s rodless chamber after the robot′s endeffector touching down the ground is eliminated. Experimental results verify that the robot's compliant touchdown control method based on the joint motion planning is reasonable.