In this study, we aim at developing a mechanical device to support humans rehabilitation motion of their wrist joint instead of or to help a physical therapist. Pneumatic parallel manipulator is introduced as the mechanical equipment from a view that pneumatic actuators bring minute force control property owing to the air compressibility and parallel manipulator’s feature of multiple degrees of freedom is suitable for a complex motion of human wrist joint. Impedance control system is introduced to realize several rehabilitation modes. The validity of the proposed system is confirmed through some experiments.