本文對《全唐詩》的同義或近義異文作全面、系統的整理、分析和歸類，認為有如下五大類型：一是異文二字的常用意義相同或相近；二是異文二字本義與引申義相同或相近；三是異文二字的常用義與冷僻義相同或相近；四是異文二字的方俗義與常用義相同或相近；五是異文二字的假借義與本字相同或相近。探討唐詩異文同義或近義的替換情況，對唐詩校釋及探究詞義轉移、滲透以及漢字形、音、義相近而相通的規律，對漢語詞彙史研究是很有意義的。

　　　　　After a thorough sorting out and systematic analysis of the pairs of different words with same or similar meanings in the Complete Collection of Tang Poetry, the author classifies them into the following six categories. Pairs of characters that are same or similar in: 1. Common or regular meaning; 2. Original and extended meaning; 3. Common and rare meaning; 4. Common and dialectal meaning; 5. Original and loan meaning; and finally pairs that consist of one correct and one incorrect character, and become same or similar in meaning when the later is revised. The author also finds that an understanding of the alternating use of pairs of different characters with same or similar meanings in Tang poetry can be beneficial for research in the following areas: 1. Shifts and infiltrations of word meaning; 2. The relationship between similarity and interchangeability in the forms, sounds and meanings of Chinese characters; 3. The history of Chinese vocabulary.