Nahjolbalahghahis a set of sermons, letters and aphorisms by Imam Ali, expressed in a brilliant style. Among these are his letters to Muaviieh. Since the content of the letters is answering Muaviieh’ s accusations, Imam Ali uses a special structure to convey the meaning. Here we want to analyze the vocal, combinational and lexical aspects of the letter from a structuralist viewpoint. The most important result is that he uses vowels like "آ، ای، او" and consonants like "ب، ج، ض، ع، غ" and “ ا، ق” , repetition, puns, which, in addition to giving the letter a sonorous and melodic, puts more emphasis on the content. On the combinational level, same-level structures are used a lot, with different relations such as Synonymity, antonymy, causation, inclusion and sequence. On the lexical level, Imam chooses tangible words to prove his legality and show the illegal nature of Muaviieh’ s reign.