為《詩經》疑難詞語訓解牽涉問題甚多，如何定其是非尤為困難。本文試著從形訛、詩境、改讀、虛實、重言詞義、構詞、多義、對文、連讀、多重訓解判準困難等各種不同類型，企圖從紛紜舊注中，考察疑難詞訓解判準依據，以建立訓詁實踐之規範。從乾嘉至民國時期，訓詁學進步快速，王念孫、王引之父子高郵王氏四種、俞樾《古書疑義舉例》、陳垣《元典章校釋例》、余嘉錫《古書通例》對於訓詁方法與理論、古書通例之歸納，做出良好示範。本文效法前賢，期望從訓解《詩經》疑難詞判準困難過程中，建立一些訓詁原則規範，以提供訓詁實踐之參考。

The explanations and interpretations of difficult words and phrases in the Book of Odes involve many issues, and the judgement of the correctness is difficult to make. This study intends to investigate different types of difficulties in establishing the criteria for explaining and interpreting false character pattern, poetic context, rephrasing, false or true situation, tautology, morphology, polysemy, dual text and continuity. Moreover, it attempts to inspect the basis of criteria for explaining and interpreting difficult words and phrases from old annotations. Based on the principle of “A grammar rule cannot be set with less than ten examples,” this study inspects a large number of difficult words and phrases in the Book of Odes. This study followed the examples of exegetical methods and theories of four principles of Wang of Gaoyou, Yu Yue’s Examples of Disputable Problems From Classic, Chen Yuan’s Annotations to Code of Yuan Dynasty, Yu Chia-hsi’s General Structure of Ancient Documents, as well as the summaries of General Structure of Ancient Documents, in order to establish the criteria for explaining and interpreting the difficult words and phrases in the Book of Odes. Finally, suggestions are provided on ten malpractices of old critical interpretation of ancient texts mentioned in Zhou Da-pu’s Studies of Exegesis, in order to strengthen the practice of exegesis.