Comparing the Songs of Chu with the style of philosophers in preQin period, the languages of the Songs of Chu have great characteristics and its tautology is one of the characteristics. Based on tautology, by using grammar analysis as main method, this paper examines the Songs of Chu from the perspective of component of morpheme of tautology, subordinating part of speech, grammatical function and so on. The results show that the part of speech of tautology is not simple but includes adjectives, echoic words, interjection, verb, adverb and other words and that the grammatical role of tautology is diversified and includes predicate, adverbial, complement and attributive.