We present an upper-limb rehabilitation robot for brain-injured patients. Its mechanical structure, working principle, control system and evaluating strategies on rehabilitation effect are described. The robot has passive, assistive and active training modes, especially, the impedance control algorithm with compensations is designed and adopted in the passive training mode. It can enhance proprioception by force control and prevent from spasm. The experiments of healthy subjects and stroke patients show that the robot can satisfy the requirement of training and is potential for clinical application.