"Kubla Khan" falls into three parts. The first thirty lines display a unity that dashes forward as if pouring out of the poet's pen unbidden—just as Coleridge describes his dream as having unfolded. Lines 31–36 pause for reflection on the scene just described, as if the poet pauses to catch his breath. The remaining lines (37–54) mark a change of subject and mood, and the consistently shorter meter creates a more controlled, intentional tone.
The first section is the recreation of Coleridge's vision while under the influence of the prescribed "anodyne," as he relates in his explanatory note. One has the distinct impression that line 30 marks the point in Coleridge's transcription of the dream when he was "called out by a person on business from Porlock." The middle section seems to be an effort to re-enter the dream. However, in the final section, the poet seems to have given up on recapturing the dream and instead provides a commentary on the creative process.
In the final section, Coleridge switches from third- to first-person narration. He recounts a vision of a "damsel with a dulcimer," and we as readers wonder whether this is part of his Kubla Khan dream. Since it alludes to Paradise Lost, we are probably right to conclude it isn't. Coleridge imagines what could happen if he were able to recreate the feelings of her "symphony and song" in himself. He would then be able to "build that dome in air,/ That sunny dome! those caves of ice!" Doing so would make him a magician with "flashing eyes" and "floating hair." He would have the power to create a vision for others, displaying what they would perceive as a supernatural ability: "And all who heard should see them [the dome and caves] there,/ And all should cry, Beware! Beware!"
The final section of "Kubla Khan" goes beyond the "vision in a dream" to acclaim the power of the poet and poetry to amaze by creating new worlds and new sensations for readers.