Ezra Pound, not only a prominent poet but also a translator, published Cathay, which is translation of 19 classic Chinese poems on the basis of Fenollosa’s notes. Since its publication, it receives warm welcome from western readers but dispute also exists due to some mistranslations. This paper aims to use rewriting theory to evaluate this work from a fresh perspective.Rewriting theory, which was proposed by Andre Lefevere, asserts that ideology, poetics and patronage would exert influence on translation. With analysis of the original work, notes of Fenollosa, it can be concluded that Cathay is under the manipulation of ideology and poetics of Pound’s era. With regard to ideology, The World WarⅠinfluences the subject Pound chose and the methods he used. On the part of poetics, Pound launched Imagism Movement against the dominant Victorian poetics. Direct images,concise language and free verse are embedded in Cathay.