A dietary treatment of Chinese medicine for diabetes mellitus was extensively studied and compared with that of western medicine. The main results are as follows: Chinese medicine is based on the following empirical dietetics. First, likeness helps likeness. When an internal organ of mankind is not functioning properly, the food or drug from the same organ of an animal will be helpful to cure it. Second, take good foods for health properly and never take any foods against body. Third, building up one's body by taking tonics is not quite the same as building up one's body through proper eating. On the other hand, western medicine is based on the experimental and scientific methods which are modernized in accordance with the development of science and technology. It emphasizes upon finding the cause of a disease. Then this disease can be cured by doing a necessary medical treatment which sometime uses a surgical operation or chemical and radiological method or both. Although there are many ways in treating a diabetic in Western Medicine, here the diabetics is supposed to be the best. The same is true for Chinese Medicine. Therefore one can easily conclude that the dietetics is the most important and effective of all irrespective of Western and Chinese Medicine as far as diabetesis concerned. In Western Medicine, a diabetic is recommened to have the minimum calories necessary for life and not to have goods containing glucide beyond a certain quantity, while in Chinese medicine a diabetic is not allowed to have foods containing more than 10% of glucide. These two facts suggest that a diabetic should pay careful attention to foods containing lots of glucide. Finally a systematic cooperation between western and Chinese medicine will cure not only diabetes but also other disease more effectively than a traditionally unilateral method.