Background: Traditional Chinese medicine (TCM) has contributed greatly to human health in past several thousand years. Today, the development of TCM is facing two obstacles: (i) quality control of herbal extract; and (ii) action mechanisms not known. Objectives: Among thousands of complex TCM formulations, Danggui Buxue Tang (DBT) is the simplest one. DBT is used to treat ailments in women and contains only two herbs, Astragali Radix (Huangqi; AR) and Angelicae Sinensis Radix (Danggui; ASR). The weight ratio of AR to ASR in DBT must be 5:1, as stipulated in AD 1247. By using DBT as a model formula, we develop a strategy to reveal the complexity of a traditional TCM formula. Results: There are 3 levels of research directions: (i) the preparation of DBT and its rationale behind; (ii) the traditional theory of DBT is elucidated by chemical and biological determinations; and (iii) the action mechanisms of DBT are revealed. Conclusion: Through the chemical, biological, genomic and proteomic studies, a possible direction in resolving the preparation mythologies, pharmacological and mechanistic analyses of a TCM decoction is being proposed here.