Using S-curve is another most commonly adopted approach in trajectory planning of robotic manipulators, since it is able to realize the time minimization of the planned trajectory with the jerk constraints and moderate computation complexity, in both the Cartesian and joint spaces. In particular, for the point-to-point task, S-curve trajectory is a relatively better candidate to minimize the residual vibrations during the robot motions. This chapter presents a modified S-curve trajectory planning algorithm with continuous jerks, in order to obtain the optimal trajectory in terms of execution time and to ensure the motion smoothness subject to the kinematic constraints. The designed algorithm can make the acceleration and jerk keep in a saturated state, which can improve the efficiency of robot programming. A multi-axis synchronization planning algorithm is integrated for enhanced motion stability in terms of the generated synchronized and continuous motion trajectories.