Abstract: The academic research of the Yishui School can be said to have two levels: one is the academic inheritance, and the best can be inherited forever which means “spread fragrance”; the other is academic tracing, expansion and innovation, which can be likened to “opening a canal” and merging “streams” into “rivers”. The second level should be the focus of current research. This article takes “Theory of Piwei” as the main example to illustrate the formation of Zhizhu Pill series, the expansion of Shengmai Powder, Buzhong Yiqi Decoction, the supplement of Qingshu Yiqi Decoction, Banxia Baizhu Tianma Decoction, the application of “Feng”(wind)medicine, and the enlightenment of some drugs. Combined with the writer's clinical experience, it is intended to show how to “open a channel” to gather “streams” into “rivers”, which is intended to show a research approach.

Key words: Yishui School, merging “streams” into “rivers”, the theory of Piwei, prescription and medicine of expanded application, Zhizhu Pill