The unearthing of Zhouyi on Silk Texts has greatly come into notice of the researchers of Yi-ology and related studies also came forth one after another. On the foundation of predecessors' studies, this thesis exclusively discusses the Chapter "Er San Zi" on Silk Texts. The whole thesis is making a comprehensive discussion and supposition through (A) the quotes from 64 hexagrams, (B) an exposition of the divinatory phraseology, (C) the gist connected through the whole thesis and some special terms in the thesis, etc. Finally, the chapter is regarded as an unabridged work, which is perfect from beginning to end; moreover, it shouldn't be divided into two independent pieces. It was likely written by Confucian scholar in the late Warring State Period.