The Koho school has a high regard for formulation corresponding to sho uniquely developed as a conspicuous feature of Kampo medicine, and Ruihobunrui (the classification of formulae based on the main crude drug : CF) has played an important role in structuring the foundation of this development in the Koho school. CF is a classification method used to express the adaptation and characteristics of formulae in the Koho school, and is useful for research on drug compositions. Therefore, CF can be used effectively in both clinical practice and education. CF has shown little development in China after the appearance of Xu Ling Tai ; however, in Japan the development of CF centered on such influential figures as Todo Yoshimasu of the Koho school, and Naohiro Kitamura of the Kosho school. Kenzo Okuda and Keisetsu Otsuka used CF for clinical practice and education during the revival stage of Kampo medicine in the Showa era ; moreover, CF had a large effect on structuring the foundation of clinical application by formulating Kampo extracts for prescriptions. Thus, CF has played an important role in Kampo medicine. However, the research has been stopped in the present circumstances of Japan. We focus here on CF of the Koho school in Edo and Showa eras, and carried out considerations of CF to establish one of the characteristics of Kampo medicine that places importance on Shang Han Za Bing Lun.