Abstract: Rhetorical cognition, as a kind of generating mechanism for literariness, has various kinds of functions in literary works. This paper first analyzes the major functions of rhetorical cognition in Hong Lou Meng, including expressing the themes of the novel, implying the fates of characters, shaping the disposition of characters, enhancing the linguistic beauty of the novel and so on. Then the three conversion patterns of rhetorical cognition in two English versions of Hong Lou Meng is analyzed, namely, from rhetorical cognition in the original text to conceptual cognition in the target text, from rhetorical cognition to rhetorical cognition and from conceptual cognition to rhetorical cognition. It is found that compared with Yang Hsien-yi and Gladys Yang’s translation, Hawkes’ translation has relatively more cases of converting conceptual cognition into rhetorical cognition, which, to a certain degree, embodies his subjectivity and enhances the literariness of his translation and its value as an independent text.