Influence is something which exists in the work of one author which could not have existed if he had not read the work of a previous author. In contrast to imitation, however, influence shows the influenced author producing the work which is essentially his own. In this article, we shall attempt to prove a literary influence of W. B. Yeats on Kim Sowall. Such an attempt must show the originality as well as the kinship of the two poets; any study of influence is not truly justified unless it succeeds in elucidating the particular qualities of the borrower, in revealing along with the influence what is infinitely more important. Sowall was influenced by Yeats; the former`s poems show traces of the latter`s. We can discern a number of significant similarities between their poems. For instance, there are very marked affinities between Sowall`s poem "Autumn" and Yeats’s poem "The Falling of the Leaves". But Sowall frees himself of the influence of Yeats and betrays his originality; thorough investigation shows that "Autumn" has materials, tonalities and sentiments which are not adopted in "The Falling of the Leaves" by Yeats. Sowall introduces the influence of a foreign poet into the Korean literary tradition.