Jaw is the most important part in human’s body, because it is an entrance of air and food. However, as we have been civilized, the function of Jaw joint is deteriorated. Compared to wild animals, humans do not need to utilize the full range of motion of Jaw joint, because foods are small enough to eat. Humans do not have to kill animals by their jaws. The deterioration of Jaw joint inflects the function of spine. Originally, humans used to open the mouths in relation to the spinal movements like wild animals. In natural and healthy body, jaw and spine move together. Many people suffering from spinal pains have a curious character, which is that the range of motion of their Jaw joints are insufficient. My trial, based on this hypothesis, is that they could retrieve natural spinal movements by doing JAW EXERCISE. “Synchronize the movements of Jaw and Spine” My trials are succeeding enough. Many patients recover from spinal pains from JAW EXERCISE. I believe that retrieving natural body is the best medicine ever. That is the philosophy of Naturalization.