This study aims at clarifying that Kim, So-Wol`s poetics is based on LiKi(理氣)philosophy. And this is to show the distinction between Western ideas like Romanticism which is accepted by Kim-uk and So-Wol`s traditional poetics. The results are as follows. First, So-Wol is realized paradoxical sense which can find out positive meaning from negative thing and overcome Western dichotomy by LiKijimyo(理氣之妙) principal means that Li(理) as Hyungisanja(形而上者: metaphysical thing) and Ki(氣) as Hyungihaja (形而下者: physical thing)are neither divided nor united. Second, So-Wol emphasizes that immutable character of Sihon(詩 魂) on his poetics because he wants to show Li`s character as inevitable cause and right. As he authorizes Sihon(詩魂) ontological and axiological character of Li, Sihon(詩魂) has Good truth and thereby has good effect for society. Unlike Kim-uk`s romanticism, to display subjectivity on So-Wol`s poetics is based on LiKi philosophy has a effect for society, because the subjectivity has a moral sensibility. Last, like Li and Ki, Sihon(詩魂) is manifested on poetry by Umyoung(陰影), so poetry is valuated by not Sihon but Umyoung. But So-Wol contradicted himself by asserting that Umyoung(陰影) isn`t discussed merits and demerits. This is explained by considering LiKijimyo(理氣之妙). Ki is a manifestation of Li, therefore when we see poetry as Ki with view is based on authenticity, Ki is not a thing of judgement. But when we poetry with view is based on substantiality, Ki is a thing of judgement. In conclusion, So-Wol intended to include not only eternal nature but also substantiality on modern poetry with LiKi(理氣) philosophy.