The science of formulas is a subject dealing with the treatment and theories of formulas, as well as the clinical application. It is an important basic course in TCM and should be studied after the Fundamentals of TCM, Diagnostic of TCM and Chinese Materia Medica courses.The textbook is divided into two parts. The first part is General Discussion, focusing on the Historic Overview of Chinese Medicinal Formulas, Treatment Methods and Formulas, Classification of Formulas. The second part includes specific discussions on formulas in 18 categories. It contains more than 360 principal formulas and associated formulas, which are divided into fundamental formulas , representative formulas and commonly used formulas. This book can be used as an authentic textbook for overseas students. Moreover, it can serve as reference for TCM practitioners with its practical content.