The motor recovery procedure during robot-assisted wrist rehabilitation for persons after stroke has not been well studied previously. In this work, we carried out a comparative study on the training effects on 10 hemiplegic persons with chronic stroke between a wrist treatment assisted by an electromyography (EMG)-driven robotic system (interactive treatment, n=5, EMG group) and a wrist treatment assisted by a clinical robot system with continuous passive motion (n=5, passive group). Significant decreases (P < 0.05) in muscle spasticity were observed at the wrist joint in both the EMG and passive groups; and reduced muscle spasticity at the elbow joint were also obtained in the EMG group (P < 0.05). These spasticity decreases were associated with the reduction of EMG activation levels during the training. The EMG-driven robot-assisted training also improved the muscle coordination capability of the persons after stroke.