Most of Chinese philosophers insist that dao 道can’t be designated by a name. among them, Taoists think that is impossible for us even know what dao is. This is because, for them, dao is a whole and it can’t be divided by anything, even by a name. but I think, this is a paradox because: if we can’t indicate what dao is, why taoists, including Laozi 老子, worte so many essays and books aobut dao? Wnag Bi 王弼 tries to solve this problem by making a distinction between ming 名(name) and cheng 稱 (designation). For Wnag Bi a name (ming) defines something in the empirical world and on the contrary, cheng is a “referred designation”. For example: if we choose same terms like “dark (xuan玄)” or “deep (shen深)” for represent what dao is, we are just using same designations (cheng) and not real name (ming). So, for Wang Bi, although dao can’t be named, nevertheless it can be indicated by same designation. My study main purports are: to analysis the difference between ming and cheng; elucidates how Wang Bi deals with the complex relation of dao and language; and finally tries to explain why Wang Bi points out the dao cannot be designated by a name (ming).