Abstract: An approach to improve the operational performance of single parallel manipulator in form of cooperation of two or more parallel manipulators are introduced. The equivalent close-loop kinematic model and kinematic equation of two parallel manipulators in cooperation are built to lay a foundation for the kinematic analysis and control of parallel manipulators in cooperation by employing the idea of instantaneous cooperating point and instantaneous constraint of workpiece and tool, thus transforming the kinematic problems of two parallel manipulators in cooperation into a solution to the kinematic problems of two single parallel manipulators, on which these parameters are restrained by the workpiece and tool. The computation for an instance has verified the correctness of the model and the validity of developing useful working space by the manipulators in cooperation.