Abstract: In this paper, the dynamics and control problems of free-floating dual-arm space robot system is studied. With the momentum conservation of system, the kinematics and dynamics of system are analyzed. It is verified that the dynamic equations of the system can be linearly dependent on a group of inertial parameters. Based on the results and with the augmentation approach, an adaptive control scheme for space robot system with unknown payload parameters to track the desired trajectory in joint space is developed. The control scheme proposed above is structurally and computationally simple, because of an effective exploitation of the system dynamics. In particular, it doesn＇t require measuring the position, velocity nor acceleration of the base. And the numerical simulation is carried out, which confirms the controller proposed is feasible and effective.