The complex level of constructing biopharmaceutics classification system of Chinese materia medica CMMBCS) was the study of traditional Chinese compound, on the premise of insisting that the multicomponent simultaneous determination, when carrying out the study of intestinal permeability, the primary task was to define the source of the components that was absorbed through the intestinal wall, namely, which medicinal material the components belonged to in traditional Chinese compound. The technology of chemical fingerprint and in vitro everted gut sac model were used in this research to make multicomponent an intuitive source attribution which permeated the intestine in the classic formula Gegen Qinlian decoction, and to lay the foundation for the further qualitative and quantitative research of intestinal permeability.