朱子淫奔詩的提出，乃《詩經》學史上重要轉折。然而自朱子倡議之際，爭端亦隨之而起，後人雖在其基礎上對淫奔詩篇目進行論說並界定篇目，但各有差異。此文則由理學角度切入，分析淫奔之人在理學上的定義，並闡述朱子對淫奔詩的定義，提出從動機而論，凡有私奔從人，不欲遵循禮節規範，並自行抒發心中之情欲者，便應歸屬於淫奔詩，從而得出〈國風〉中應有二十七篇詩歌可符合朱子淫奔詩的定義。

The publishing of Chu-Si’s obscene poem is an important transition in the research history of ‘the Book of Songs”. Arguments came along with Chu-Si’s advocacy on the obscene poem and the posterity had further made definitions on chapters of obscene poems according to its basis, but with differences. This study bases on the theoretical perspective to analyze the theoretical definition of the “obscene people”, expounds Chu-Si’s own definition on Obscene Poem and concludes that bases on the motivation, who run away with others but on his/her own will, shall belong to the category of obscene poem. Therefore, twenty-seven poem songs in “Kuao-Fong” conform to Chu-Si’s definition on obscene poem.