Indication and functions is an important key information in the research and development of the ancient classical formulas, which directly affects the clinical positioning of the compound formulas and their reasonable, effective and safe use after marke-ting. It is also the embodiment of the ultimate vitality of ancient classical formulas. Due to the particularity of ancient classical formulas, it is of great significance to accurately define and describe the functions and indications of classical formulas to exert their unqiue advantages. Based on the analysis of the provenances, classification of clinical indications, and functions of 100 prescriptions in the Catalogue of Ancient Classical Formulas(First Batch), this paper summarized the incompleteness, irregularity and inconsistency in the original text, the differences in terminology between ancient and modern times, and the evolution of the meanings of prescriptions in different dynasties. In addition, under the guidance of the general principle of textual researh on ancient classical formulas, which is to inherit the essence, make the past serve the present, link up the past and the present, and bulid consensus, this paper proposed the following ideas: respecting the original meanings and provenances of ancient classical formulas, taking full consideration of the development and evolution, serving the current clinical application and health needs, accurately linking up the ancient and modern terminologies, standardizing the expression of traditional Chinese medicine(TCM) terminology, highlighting the characteristics of TCM, attaching importance to the textual research principles and suggestions of post-marketing evidence-based and clinical positioning research, so as to determine the the functions and indications of the ancient classical formulas in a scientific, standardized and reasonable way and better guide the clinical application of the classical formulas.