The research is to recognize the roles and essence of the Six Classics and the book of Changes on the points of Chang Hsueh-ch’eng’s view in I-chiao〈易教〉. Firstly, explore his interpretation of the Six Classics. Considering the Six Classics is a chronology record of the dynastic histories, Chang not only reveals he preeminent thinking of lin-chin-chieh-shih (the Six Classics are records of history)「六經皆史」, but also trys to find out the essential unity among. Secondly, Basing on the I-chiao〈易教〉interpretation points analyzes and addresses the unique perspectives of I 《易》in the Hsia、Shang(Yin) and Chou Dynasties. Furthermore, asserts that Chou-I《周易》 has the capacity of governing the statecraft to reach toward the greatest usage; and the Lien-shan《連山》and Kuei-Cang《歸藏》are as books of divination. Finally, cross reference to obtain the mutual content between Taoism (道) and Calendar (曆法).