JebyeongwonhuronㆍYobaebyeonjehu is well organized and detailed is stated of classification and cause, mechanism of lumbago. That is divided into nine classes according to cause and symptoms of lumbago and described those respectively. Although there is some different, classification of lumbago after ages is based on this method in the main. The outbreak mechanism of lumbago can be stated that wicked germ invade into the body in condition that spirit and energy, especially the kidney energy is poor through various reason. That is stressed on interior factors. In the relation to organs, it is inferred that outbreak of lumbago have connection with the kidney deeply.