This disse-rtation attempts to reread Yeats''s poetry by applying not only the theory of ideology in contemporary Marxist criticism but also Raymond Williams''cultural theory and Ernest Renan''s notion of nationality. In Yeats''s poetry, we can find three different aspects of cultural nationalism: (1) the patrioticculture or nationalism of the bourgeois; (2) the cultural or literary nationalism of the Young Ireland movement; and (3) the romantic, political,or revolutionary nationalism. These three aspects correspond to the three features of Raymond Williams'' cultural theory: "the Dominant, the Residual, and the Emergent." In addition, there are two kinds of patriotic nationalism in Yeats''s poetry: (1) the emotional natioanalism of Catholic Ireland and the intellectual nationalism of Protestant Ireland. Yeats disapproves of the firstkind, which is characterized by inheritance and pure emotion, but approves of the second kind, which emphasizes a choice of the mind or intellect. Further, this dissertation also adopts Renan''s notion of "nationality as a soul or a spiritual principle"; Renan''s notion resembles Yeats''s concept of Irish nationality as an intellectual idea or a spiritual life and, in a larger sense, Yeats''s mystic concept of the great mind or the universal mind which is the underlying principle of many of his poems.