William Butler Yeats,one of the most important figures in the transitional period from Romanticism to Modernism, struggled for a systematic updating of subject matter and style throughout his literary career and wrote extraordinary poems in every school he was involved in whether it was Post-Romanticism, Aesthetism, Symbolism or Modernism. Since it is the achievement of the poety of the Symbolism, helped him finish the transition from Romanticism to Modernism, and attained a high position" modern romantic lyric poet" in the republic of letters. Yeats occupies a central place in the history of English literature in the 20th century. As a prolific writer,his works cover poem,drama,prose,short story,autobiography,philosophy and literary critic, the archivement of poem is outstanding.

Poetical creation of W.B.Yeats is divived into 3 periods. And every period has its typical symbol to express the writers thoughts.

Yeats published the anthology of poems The Wild Swans At Coole in 1919 marked the beginning of the second period. Swan is central symbol in this time. In the year of 1897, Yeats received the invitation of his friend Lady Gregory to summer in Coole, and he was amazed to find a strange kind of life style-the titled classes' life during this wonderful time. Swan can be represent his whole thoughts,emotion and ideality of life and politics.

He seemed find panacea to rule the confused modern society and calm down his inner world. The swan is a true portrayal of the titled classes'.