Abstract: Concepts like "yong-yi" "say something in your mind" and "meaning belonging to something" in Huang Tingjian's poetics are the medium between rhetoric like "the way of making a sentence", "keys in a sentence" and culture like "xin and xing" "reading".Their essence covers both "xin and xing" and "insight"; their application means "idea" should cover both the ancients' words and things-outside.However, the meaning of these concepts is different from a simple "keeping xin and xing", not just the allegory form of poetry, and beyond the moralist's "guan-wu" theory.Their complex texture marks the fundamental change in the way of perception of poetry in Song Dynasty.This change provides not only a better understanding of Huang Tingjian, but also an effective view on the poetry in Song Dynasty.