Abstract: The metaphoric pattern of“A as B/X as Y”that often appears in Tang dynasty poetry is a rhetoric structure. From the perspective of the Chinese rhetoric history, the formation of the pattern relies on the evolution of the Chinese figures of speech, the development of poetic language, and the prominence of the language’s metaphorical function. This pattern has its structural stability, reproducibility, and specific function. It has a constant form and a variant version, in which the two comparative words fall on either the second and sixth or the third and sixth places respectively in a line of the seven-character verse. Metrically, the ways of word agglutination vary due to the different positions of the comparative words. In this“A as B/X as Y”pattern, the choice of analogous words also has is uniqueness.

Key words: rhetoric structure, Tang dynasty poetry, A as B/X as Y, metaphor