A robotic system for rehabilitation using EMG signals to provide mechanical help includes EMG electrodes (6) sequentially connected in series, a DAS card (2) and a control portion (1), and further includes an actuator (3) connected to the DAS card (2) and an additional moment providing portion (4) connected to the actuator (3). The EMG electrodes sense EMG signals corresponding to the muscle of suffering joint, and input the sensed EMG signals to the control portion (1) through the DAS card (2). The control portion (1) uses the input EMG signals and a constant moment set as desired to calculate an additional moment to be applied to the suffering joint, and additional moment providing portion (4) is controlled to apply the corresponding additional moment to the suffering joint through the DAS card (2) and the actuator (3).