漢字為藉形表義的書寫系統，形構構件中則以形符擔負表義功能。部首，為構件之一，而許慎於《說文》所建構之部首系統，依共同形符將字頭派入不同部首，井然有序地將九千餘個字頭歸納成五百四十個義類，同時也奠基了後世字書以形符歸部之走向。據此脈絡，部首當確實具備表義功能，故於今之漢字教學中，常藉由部首引導學習者識字及習寫，即所謂「部首識字」教學法。然而，文 字經由小篆、隸書演變成楷書，歷經形體簡化及筆勢化等變異過程，部分形符構件喪失了原來的構意，又或原屬不同來源之形構， 簡化後演變為相同形體；加以字書為檢索之便，將五百四十個部首整併為二一四部，併合部分義類。就上述歷程推論，部首之表義功能或將因此減損，故本文嘗試以王寧先生提出之漢字構形分析教育部《常用國字標準字體表》中之「田」部字，試圖探索於今二一四部首系統下之部首表義功效。經分析作為樣本之25個「田」部字， 部首表義者占64%，初步來看，「部首識字」教學法具有一定程度之可行性，惟未能表義之36%，同時說明了須審慎為之的必要性。

Chinese character is the writing system of shape shows meanings, and the radical plays the role. Xu Shen's "ShuoWen" got together 540 meaning from approximately 9,000 parts of Chinese characters, and that is the basic of radicals.Nowadays, Chinese characters' teaching is often used to help learners to know or write Chinese characters. But some of radicals lost the original meanings because of evolving into different shapes for writing easily；other different radicals become the same meanings. In order to search conveniently, 540 radicals be merged 214, and the meanings also be merged. The function of radicals show meanings maybe affected by evolving and merging. This article refer to Wang Ning's theory of Chinese character's form and shape to analysis Chinese characters of radical "田" within Ministry of Education's "Frequently Used Chinese characters" and discuss the effect that show the meanings within 214 radicals of "ShuoWen".In 25 Chinese characters of radical "田" analysis, the function of radicals show meanings 64% is correct, and 36% is questionable. Although radicals recognize Chinese characters teaching is practical, it still need to be worked deliberately.