Seok-joong Yoon called as a great master of children’s songs created about 1300 children’s song poems for 80 years. The central point of his extensive literature is a child’s mind. His mind of a child can be summarized as follows: It has no border and can talk with animals and plants, trees and stones, and all nature in the world. In his collections of poems How Thankful It Is and So Nice To Meet You that were published when Yoon was over 80, he said “hello”to nature such as animals, stones and plants. He recognized human being and nature in the same position like a child in these collections of poems, and his recognition was de-egocentric by giving the equal personality to objects or each part of body that we usually think just as useful medium, through having a positive conversation such as“ How thankful it is” or“ So nice to meet you”, and shaping ethical relation to them. Yoon’s rocognizing style reveals that human is not the only being that reigns over nature, ruins the environment and treats the life lightly by objectifying nature and the matters, based on the man-centered thoughts, but as a part of the nature, we should live together with them. His ecological recognition that is reflected in two collections of poems published when he was over 80, can be interpreted as his comprehensive recognition of literature, from the point of the evening of his life. In this material dominated, exceedingly competitive society, the ecological recognition of the world reflected in the collections of poems How Thankful It Is and So Nice To Meet You shows a way to harmonize human being with nature by our getting out of egocentrism and materialism. Also, it’s very meaningful to prevent human being from oppression by materials and let them think worthy themselves.