Yi Trigrams can be traced back to about eight thousand years ago. From the period of Fux Xi to the dynasties of Xia and Shang, yi Trigrams developed for more than eight thousand years. From the great number of tangible archelogical materials that have been discovered, we are convinced that Yi Trigrams is the foundation and source of Yi Jing, which is the evolution, development, sublimation and mutation of Yi Trigrams. The relation between the two is the development from gradual transformation to mutation, as well as the inevitability from the quantitative to qualitative changes.