We develop exoskeletal robots for the motion support of physically weak persons. In this study, the human elbow motion is assisted by the exoskeletal robot system, since the elbow motion is one of the simplest and the most important motion of human beings in everyday life activities. The angular position and impedance of the exoskeletal robot system are controlled by multiple fuzzy-neuro controllers. The skin surface electromyogram (EMG) signals and the generated wrist force by the human subject during the elbow motion are used as input information of the controller. Since the activation level of working muscles tends to vary with the human subject's arm posture, an intelligent interface that cancels out the effect of posture changes of the human subject's arm is proposed in this paper. The experimental results show the effectiveness of the proposed intelligent interface.