Abstract: Traditional Chinese medicinal materials (TCMMs) are the material basis of the traditional Chinese medicines (TCM) in the treatment of disease, and the inherent quality of the TCMMs are of crucial importance for the efficacy and safety of TCM. Most of the TCMMs are originated from the plants with complex chemical compositions, and the chemical diversity is inevitable. How to clarify the relationship between the chemical identity and the biological activity is the key point for quality control of TCMMs in the establishment of the quality standards. The components with great impact on the biological activities should be used as index compounds in the quality evaluation. In this study, based on the results in our previous studies, a research idea on the evaluation of quality difference of TCMMs is proposed. Its application and existing problems are also discussed.