The virtue of Manhae`s poetry is what it doesn`t lean to any side. In this case the problem about poetry and Zen can be occurred at first. Zen usually uses converse logic and illogic. The world of enlightenment which is the goal of Zen can be revealed with converse logic and illogic. This means both contradiction and paradox at the same time. The contradiction and paradox are the essential logics which people can understand poetry with. They show complex layers of meaning. The layers of world are the complexity of structure. The complex fractal structure which is shown at his poem ＜I Can`t Know＞ and collection poems ≪Your Silence≫ reveals the complexity of universal existence aspect. The structural beauty covers both Zen and poetry. Whatever it is Zen, or poetry, that`s why the structural beauty is revealed with language. In this point of view the important thing is that Zen and poetry through language or the tension between structure of Zen and poetry`s structure. The tension between Zen and poetry keeps one world from leaning to the other one. That`s why ＜I Can`t Know＞ and ≪Your Silence≫ show the world of Zen deeply and beauty the world of poetry has totally. If it is the virtue of Manhae`s poetry, the important thing in criticizing and interpreting his poetry is the structural tension between Zen and poetry that are formed by language.