The open-closed-pivot theory of three yang channels in Huangdi Neijing（ Inner Canon of Huangdi）explains three kinds of qi movement of three yang channels. The theory is embodied in six-channel syndrome identification of Shanghanlun（ Treatise on Cold Pathogenic Diseases）. Prof. ZHANG Xuewen has deep experience of this theory and respects WU Kun’s（ a famous doctor in the Ming Dynasty） view on greater yang is the opening

yang brightness is the closing and lesser yang is the pivot. Prof. ZHANG also proposes that treating incurable diseases should follow this theory.