本文主要分析乾坤二卦的關係，及其衍生出來相關的思想問題。本文認為，乾坤居六十四卦之首，顯示純剛純柔發揮到極致的情況。《易經》作者同時強調，乾中有坤，坤中有乾，乾坤是互相依存的兩種力量。因此，《易經》的宇宙論是乾坤互動、健順互推。從文本上考察，乾坤之上並沒有一個更超越的本體。 其次，《易經》的乾坤關係，乾中有坤，坤中亦有乾。但二卦的關係，乾為主，坤為從，這在卦爻辭中可見可證。《易經》所描述的「道」體，雖然是乾坤相盪、剛柔互推，但其整體精神則是主剛健而不主柔順。《易傳》承繼了《易經》乾坤互動及主剛健的原則。《繫辭傳》提出「一致而百慮」，「一致」講的就是《傳》文所說的往來、屈伸之理。這種往來、屈伸之理，與《易》乾坤互動及主剛健的原則是符合的。

　　　　　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”.