This paper first makes a distinction between the concepts of Semantic Fuzziness and Pragmatic Ambivalence, then, it poins out what criteria can set them apart. Next, it explores how speakers exert pragmatic ambivalence and how listeners get rid of the ambivalence in language. Finally, this paper summarizes the pragmatic functions of pragmatic ambivalence. The purpose of this paper is to make clear the dividing lines between semantic fuzziness and pragmatic ambivalence and divert more scholars' attention to pragmatic ambivalence.