《說文》是一本研究漢字字形結構和字義關係的書籍，因此，全書在體例上就特別強調這兩者的統一性，而透過字形結構的分析，直接顯現出文字本身所代表的意義，是許慎寫作時的規律。然而，經過材料的分析以後，卻發現《說文》在解釋部首字義與字形時，往往產生矛盾的現象，過去的研究者，對於這種矛盾現象的看法，比較偏向於是現在流傳的本子有脫漏的現象，或者認為是許慎在解釋字義上不夠精確的緣故，但是都不能總結出一個結果來。因此，本文專就這種特殊的現象，經由整理分析後，推測其可能之原因。

Shuo Wen is a book investigated the relationship between the configuration of Chinese characters and the meaning there of, therefore, the consistency of them will be emphasized through the text .The rules which Xu Shen used to write this book is to present the meaning of a character directly by analyzing the configuration of it. However, contradition was encountered when Shuo Wen explained the meaning and character of radicals. The researchers of the past thought this contradiction was due to the lacuna in the book or the impression of meaning explanation, but none of them can be confirmed. Therefore in this article, a possibility about this phenomenon has been predicated through the analysis and synthesizing.