Abstract: Every robot, like the human-body, has its allowable range of joint angle. In order riot to exceed the allowable joint ranges, previous studies proposed ail optimization algorithm, which employed surplus joints of robots to prevent joint-limit violation. However, this algorithm does riot fully utilize the entire motion range of joints because this algorithm controls the joint angle to come close to the middle position of each joint's range. Also, it consumes relatively large kinetic energy. This paper proposes a new motion planning algorithm that prevents joint-limit violation, utilizes a wide motion range of joints and minimizes the kinetic-energy consumption. The feasibility of the proposed algorithm was verified through a simulation study of several example manipulator models having surplus joints.