Current studies on metaphor translation mainly focus on exploring how conceptual mapping facilitate the transfer of information and images from SL to TL without paying enough attention to metaphor's rhetorical function in target texts.After summarizing metaphor's discourse functions in previous rhetorical studies,this paper makes an in-depth analyses on metaphors in CPC leaders and government officials' speeches as and their translated versions.The paper claims that metaphors' role in facilitating the explication of political concepts and their persuasion power should be taken into account when choosing translation strategies.And in translation practice,such translation methods can be adopted as literal translation,translation plus sense,replacing the image,translation by simile,and interpreting the metaphorical meaning,so as to enhance the country's global communication effect.