The purpose of this essay is to utilize the elucidation of Duan Yucai and other contemporary scholars for such exegetic terminologies as “Du Wei,” “Du Yue,” “Du Ru,” and “Du Ruo” to explore whether these terms can be theoretically verified in Zheng Xuan’s annotation on Li Ji. Through discreet examination and verification, I am capable of discovering few exceptions which can not coincide with above-mentioned exegetic terminologies. Therefore, the author intends to classify these exceptions into five categories, and then divide them into three groups for discussion respectively. For one thing, I will give some concrete examples of universally scholastic consensus. For another, I will employ some explanations of contemporary or late scholars as Han Xu, Lu Deming, and Kong Yingda, based on the foundation of Zheng Xuan’s exegetic methods, to achieve comprehensive discussion and clarification and to expect to remind the readers to make sense of the contentions of Zheng Xuan and late scholars. Whether these great scholars’ arguments leave much to be desired or not, I sincerely hope that I can make every effort to display exegesis of great value in judging ancient books.