The underwater vehicle-manipulator system (UVMS) generally has more degrees of freedom than those required to perform a given task. Because of these extra of degrees of freedom, UVMS has infinite combinations of joint velocities. In this paper, in order to generate the joint angle trajectories of the manipulator, a redundancy resolution is performed to minimize the distance between the position of ZMP and the mass center of the underwater vehicle. Proposed algorithm helps the whole system to keep the dynamic stability while the UVMS conduct a given task. To evaluate the proposed ZMP algorithm and redundancy resolution method, a testbed composed of redundant manipulator was developed. The results show that ZMP algorithm helps the stability of the UVMS while the end-effector of the manipulator tracks the desired trajectory accurately.