Abstract: On the basis of the dynamic equation of single flexible robot, the kinematic and dynamic coordinated constraints are established for the cooperation system, using the linearized differential relationship in a closed-loop linkage. The general dynamic equations of flexible-manipulators cooperating rigid closed-loop linkage are then developed, for the first time, based on the standard kinematic parameters of the payload task. A simulation of two planar 3R flexible robots manipulating a four-bar linkage is illustrated successfully.