Basic research of categorized formulae (CF) is one of the approaches to understand the scientific basis of formula assembling and syndrome differentiation in Chinese medicine. In this paper, the common features of CF researches were discussed. The authors held that the four issues, namely, the links between CF-syndrome-diseases, the compatibility of herbs in the core of CF, the comparison of similarities and differences in various kinds of CF, and the identification of effectual substantial basis of CF, are the kernel problems should be solved in CF research, also the scientific intension for elucidating the complex series of Chinese medicine prescriptions, revealing the rules of formula assembling and developing new drugs.