In the rehabilitation, the real executive movement has been considered the main tool for motor recovery and motor learning. Many studies reported that active exercising creates a flow of sensory information which can change neuroplasticity. Recently the numerous studies report that both the imagery and the observation of a movement increase corticospinal excitability of primary motor cortex and activation of M1 area similar to the real execution of the movement. And the studies also report that these central activations occur in a specific manner. Now many people consider the imagery and observation can be a new therapeutic tool in rehabilitation especially for who can not execute a real motion at all due to neurologic deficit. We will review the articles reported the central nerve system changes by the imagery and observation of an action compared with the executive motion. And most of these experimental studies were based on the results of the healthy subjects, we discussed about the limitation of these therapeutic strategies according to the aging process and to the brain dysfunction.