Rehabilitation robot is usefully to improves walking ability on patients with gait disorders. Over the last decade, rehabilitation robot device replaced the training of overground and treadmill. The purpose of this study was to compare the differences in muscles activities of simulated human leg while walking on two gait rehabilitation robots: the exoskeleton rehabilitation robot and the end-effector rehabilitation robot. We have built models of simulated human leg, exoskeleton rehabilitation robot and end-effector rehabilitation robot. The results showed that rectus femoris and tibialis anterior muscles of the simulated human leg were more active while walking on the exoskeleton rehabilitation robot. The results of this study may provide technical improvement for gait rehabilitation robots, so that lower limb muscles movement can be more correctly achieved for normal individuals during gait rehabilitation training.