This study is on the etiological factors of the obesity, symptoms of a disease caused by the etiological factors and the method of medical treatment resulted from symptoms of a disease, it is based on Dong-Yi Bo Gam. The conclusion of this study is as follows. 1. The final metabolic of fat is depend on the defensive energy. The shape of fatty layer is changed by the point where the defensive energy is replenish or not. So 'Goin(暠人)' 'Bein(肥人)' and 'Yuckin(肉人)' is made a discriminated and there is defferent between 'Besudaeso(肥瘦大小)' and 'Herlqidaso(血氣多少)'. 2. Etiological factors of obesity is ; essential substance from cereals overcome the primodial energy, spleen and stomach are strong at once, spleen and stomach are weak at once, spleen is disturbed by evil energy, retention of phlegm and fluid, muscle is weak, blood is excess but energy (qi)is weak, hua-sid(華食) eating the sweat food very often, a rich fatty diet. 3. To investigate each syndrome as etiological factons, essential substance from cereals overcome primodial energy is divided into two case: one is the food increase itself because of the weakness of stomach energy (qi), the other is not to digest the food because liver overact spleen by seven emotion. The obesity because of strengthen of the spleen and stomach at once do not feel hungry very well and spleen and stomach do not damaged easily by overacting. The obesity because of weakness of spleen and stomach at once, and disturbace in spleen cause by evil energy, gain the weight even if they eat food a little. Also it is hard to move four limbs. Weakness of muscle is weakness of spleen and stomach. Weakness of muscle is caused by weakness of spleen and stomach. That is the case of faining the weight because of eating food with an empty stomach. The obsity caused by retention of fluid has intestine rumbling and gain the weight suddenly. 4. The method of medical treatment fallowing to the etiological factors: The food is inclined to increase itself caused by weakness of stomach energy, In case of the obseity caused by this phenomenon. We can use Decoction for Reinforcing Middle wanner and Replenishing Qi(補中益氣湯), five tastes il-going-san(左味異功散) and so on. The method of medical treatment on obsity caused by strengthen of spleen and stomach is not referred yet. But we must investigate about using peptic powder(平胃散), ji-chul-huan(枳朮丸) for strengthen of stomach qi (胃氣). If the obesity appear caused by weakness of spleen and stomach and disturbance in spleen as to evil energy, and in the same time stomach qi is weak, we can use li-gong san(異功散). If not only obesity but also indigestion, we can use Decoction for naurishing the stomach and promotion eating(養胃進食湯). If not only obesity but also weakness of spleen and stomach, we can use Decoction for Reinforcing Middle warmer and replenishing Qi(補中益氣湯). The energy being weak, we can use Decoction for six noble drugs(六君子湯). If the obesity appear because of retention of fluid, we can use sin-chul-huan(神朮丸). On the obesit, caused by excess of blood and weakness of qi(血管氣虛), there is not method of mectical treatment yet, but the method of medical treatment that we count of first important maybe to invigorate the spleen and the lung qi and to disperse and recitify the depressed liver energy(疏肝利氣). The method of medical treament about the obesity caused by a rich fatty diet is not mentioned yet, but it is important to improve the lifestyle of food and we think that invigorate the spleen, and the lung-qi(補疏肝氣) and disperse and recitify the depressed liver-energy (??肝利機) amy count of first important. 5.There is useful medicine for weight down for example Herb tea(茶), red bean, wax gourd, etc. 6.The etiological factors of the obesity that revive frequently is weakness of qi(氣虛), from 形成氣衰, deficiency of yang, hasty of qi, damp and so on. The symptoms and sign of a disease that revive frequently to the obesity is appoplexia(中風), leucorrhea, reddish and whitish turbid, feeling of fullness in the upper abdomen, diabetes and so on.