This paper focuses on the similarities and differences between Robert Browning's dramatic monologue and W. B. Yeats's mask theory. Even though two poets were not contemporaries, it is very interesting that they show some similarities in poetic skills and subjects. Unlike Romantics revealing a poet's subjective feeling directly in their poems, Robert Browning created the dramatic monologue to develop the field of the objective expression. In his “dramatic monologue,” a character instead of the poet utters the speech that makes up the whole of the poem, in a specific situation at a critical moment. This person addresses and interacts with other people and we know of his presence, as well as what they say and do, only from the clues in the discourse of the single speaker. In his “My Last Duchess” the Duke is negotiating with an emissary for a second marriage, and the reader can know the speaker's cruel character and intentions. In his “Andrea Del Sarto,” though Andrea was one of the greatest painters in the Renaissance period, he was a failure as an artist because of his artistic passion and indomitable spirit. Excusing his artistic frustration, he once more tries to believe his wife's lies. When Yeats entered art school in Dublin in 1884, he was an enthusiastic reader of English poetry, especially Browning. Yeats was an admiring reader of Browning's poetry, and Browning was one of the nineteenth-century forefather poets of Yeats. He explored, as Browning did, the themes of creative men divided within themselves and struggling to unify their inspirations toward love and intellect, aesthetic contemplation and heroic action. In this process, Yeats developed the concept of masks from the other self in contrast to the natural self perceiving a man as the conflicting existence between subjectivity and objectivity. In his doctrine of mask, Yeats provided a formal aesthetic for the poet's need to speak dramatically through the masks of other personalities; Browning had long practised dramatic poetry in principle in which he donned the masks of personalities totally unlike his own. Browning tended to hide his interests behind the masks of his characters, whereas Yeats more openly voiced a variety of mystical and antithetical thoughts. Yeats happened to find an occasional, almost incidental similarity of language and a shared attitude toward the sources of poetic inspiration with Browning's. By 1929, when he was sixty-four years old, rewriting and revising his poetry with an eye to a collected edition, he announced that he would be turned from Browning. Yeats was an appreciative reader of the older poet, but the great achievement of Yeats's poetry transformed and transcended the influence of Browning.