[1] The Korea Literature Translation Institute describes Yu: He began his career in poetry with the publication of "Tranquillity" (Jeongjeok) in Literary Arts Monthly (Munye wolgan) in December 1931.

The publication of his first poetry collection, Poems of Yoo Chihwan (Cheongmasicho), in 1939 was followed by some ten further volumes of poetry, including The Chapter of Life (Saengmyeong-ui Seo), The Isle of Ulung (Ulleungdo), Journey of a Dragonfly (Cheongnyeong ilgi), as well as a book based on his experiences in the army during the Korean War, Together with the Infantry (Bobyeonggwa deobureo).

On one hand, within the historical dimension represented by the extreme circumstances of the late years of Japanese Imperialism, there appears a masochistic rage and a savage will, while on the other we find, within the death predestined for humanity, a compassion and pathos for existence.

These parallel portraits of the life-force and pathos are aptly illustrated in one of his best-known poems, “Flag” (Gitbal).

Because of his endeavor, based on this violent love of the life-force, to overcome by strong force of will the essence of nothingness, Yoo Chihwan is known as a poet of the "life-force" or "life" schools; and because of his poems' smooth recitation of sublime poetic themes, the critics see in his works a masculine poetic world rarely viewed in modern Korean poetry.