Abstract Based on the analysis of the rules presented by Explanation of Nouns and some examples of misreading of the book,this
paper discusses the characteristics of Explanation of Nouns in its explanation of Chinese characters,that is,it makes full use of the
polysyllabled words formed by explanatory characters with indication of
pronunciation.Firstly,the paper studies the three structures of polysyllabled words formed by explanatory characters with indication of pronunciation as rendered by Explanation of Nouns,namely,the compound words,the words that consist of two characters with the same pronunciation and the words with suffixes.Secondly,the paper examines the functions of the polysyllabled words formed by explanatory characters with indication of pronunciation,making clear whether the explained character and the homophone are of the same origin or just homonyms,and determining the meaning and part of speech of the word.Thirdly,the paper points out the weakness of Explanation of Nouns in its breaking up of Lian Mian Ci(a group of words that form a term,an expression,or idiomatic usage,which will be meaningless if separated).