「一陰一陽之謂 道」為〈繫辭〉中談論「道」內涵的重要詞句，此關係著易學形上觀念的建構，然歷來註疏家解釋皆有不同，何者為是呢？為本文企圖由歷代重要註疏家中挑選四家，分別為王弼、朱熹、王兼之、高亨先生四人，先分別說明他們對「一陰一陽之謂道」句的解釋；再者，分析他們說法的背後的可能依據及與〈繫辭〉原文的相應關係；最後，則歸納他們的說法，為「一陰一陽之謂道」句尋求更豐富得詮釋。最後將「一陰一陽之謂道」邀納出幾種結果：一類視道為理則、規律，不限於形上形下，含括形上形下；一另類則視道為形上結構，只限定於形上層次討論。就第一類而言，當周區分為二，其一即視陰陽為特質、屬性；另一則視陰陽為二氣。就第二類而言，陰陽皆視為二氣，然亦有兩種解釋角度，一就存有論的角度；另一種則混存有論與宇宙論而論。而以上這些詮釋，基本上皆「一陰一陽之謂道」所含而可以成立。

The axiom “Yin and Yang is so-called Dao (Logos)”, an significant sentence in interpreting the meaning of Dao (LOgos) in Ji-Tsu (繫辭), is related to the construction of I-Ching’s metaphysics. The maters’ interpretations are various in the history; however, which one is more relevant? I chose four critics: Wang Bi (王弼), Ju Si (朱熹), Wang Fu-je (王夫之) and Kao Hen (高亨) to discuss. First explain their interpretations aobut the axiom. Then, analyze the potential base of their interpretations and relate their interpretations with Ji-Tsu (繫辭). Finally, generalize their criticism to make the explanation of the axiom more a abundant. I got two conches. The first one shows that Dao is a kind of regulation and occurs to both metaphysical and physical field. this concept contains two kinds of thoughts. One views Yin and Yang as distinguishing characteristics, and the other views them as two kinds of air. The second one shows that Dao only occurs to metaphysical field, and Dao could be divided into two kinds of air. This concept contains two kinds to thoughts, too. One is concerning ontology, and the other is concerning both ontology and cosmology. And basically, these interpretations all are revenant to the meaning of Dao.