William Wordsworth wrote Preface to the Lyrical Ballads in which he advocated his own theory of poetry. This theory was a new taste for the reader especially in the matter of theme and style. Wordsworth’s theory of poetry aims at writing poetry against the neo-classical theory of poetry, as Neo-classical theory of poetry is totally based on the aristocratic life rather than rustic life. In Preface to the Lyrical Ballads, Wordsworth gave a new pattern to write poetry and he discusses its purpose too. He advocates that the theme should be adopted from the common ‘incidents and situation’; the language should be from common man’s life; poet should write as a man and then the ‘poetry is the spontaneous overflow of powerful feelings recollected in tranquillity’. This paper aims at presenting Wordsworth’s theory of poetry with special reference to the poem “The Solitary Reaper”.