This paper mainly discusses the philosophical relationship of the two hexagrams “qian” and “kun”. We draw the following conclusions: 1.In the paragraph of the “qian” hexagram of the Yijing, we can find word interpreting the concept of “kun”, and , in the paragraph of the “kun” hexagram, we can find words interpreting the concept of “qian”. 2.The two hexagrams are interrelated, indicating the dialectical relationship of the two opposite forces (positive and negative, hard and soft, active and passive) of the universe. According to the original text, there isn’t any transcendent ontological origin above “qian” and “kun”. 3.Although the cosmological structure of the theory of “change” is built up by the power generated form both “qian” and “kun”, the dynamic movement of the universe is mainly phased by the positive force of “qian”. To a certain extend, we should say the main spirit of the theory of “change” is positive and active. 4.Yizhuan inherited the spirit of the Yijing. The word “yi-zhi” (一致) in the Xicizhuan also indicates the philosophical relationship of the two concepts “qian” and “kun”.