Objectives : The purpose of this study is to consider the definition, history, classification and clinical effect of balneotherapy. Methods : We researched oriental documents and recent sources of balneotherapy. Results and Conclusions : 1. Balneotherapy is medical cure method which uses physical chemistry effects of water. 2. Records of balneotherapy are seen in oriental documents such as Hwangjenaegyeong(黃帝內經), Sinnongbonchogyeong(神農本草經), Jaebyoungwonhuron(諸病源候論), Youmoonsachin(儒門事親), Bonchogangmok(本草綱目) and Donguibogam(東醫寶鑑) etc. 3. Spa can classify eleven types according to ingredient. The types were as following. Simple thermal spirng, Common salt spring, Sodium bicarbonated spring, Sulfate spring, Radioactive spring, Acid spring, Sulfur spring, Carbon dioxide spring, Iron spring, Alum spring & Sulfate-iron spring, Bicarbonatealkaline spring. 4. Physical, chemical and environmental effect of spa therapy have effectiveness on the chronic and we akness disease more than acute disease. And balneotherapy have more effectiveness on digestive disease, pulmonary disease, metabolic disease, circulatory disease, muscle skeletal disease and dermatologic disease than any other diseases.