鄭玄的周初年代編排，係據「殷曆」推算，此於鄭氏〈豳風〉、〈周書〉的箋注中可以驗證。後世學者因不明鄭氏據「殷曆」推排的周初年代學，故在解釋鄭氏〈周書注〉時，眾說紛紜，且多舛謬。本文據「殷曆」還原出鄭氏的周初年代表，在此基礎上考察清代學者以今、古說歸類鄭學所存在的問題，並進而討論今、古之分同樣不能圓滿解釋鄭宗《周禮》的現象。因此，在研討鄭氏經學時，除今、古之分的視角外，還應探求鄭氏的立論基礎。

That Zheng Xuan arranged the chronology of the early Zhou dynasty according to the Yin calendar is a fact that can be verified through Zheng’s annotations of “Binfeng” and “Zhoushu.” Because later scholars failed to understand Zheng Xuan’s Yin calendar-based chronology, these scholars’ explanations for Zheng’s annotations to “Zhoushu” are all quite different and largely erroneous. This article uses the Yin calendar to restore Zheng Xuan’s chronological table for the early Zhou dynasty and, upon this foundation, seeks to examine problems apparent in Qing dynasty scholars’ new and old text classifications of Zheng’s theories. Additionally, this article discusses how the distinction between new and old texts is equally unsuitable to provide a satisfactory explanation for Zheng’s veneration for Zhouli. Thus, when discussing Zheng Xuan’s work on the Confucian classics, we should not only consider the differences between new and old texts, but should explore as well Zheng’s arguments and their foundations.