Yao Pei-Chung was a image-number system of Yi-ologist of the Ching Dynasty who is good at the Yi learning. His writing about Yi books has been mostly focusing on Yi study of Han Dynasty. Yao Pei- Chung liked《Yu Shih's Yi》written by Chang Hui-Yen the most. He thought Cheng Hsuan was the best of those scholars who explored the Yi learning during Han Dynasty. This essay will explore and analyze in details to the history, the thinking and idea, as well as the specialty of his Yi learning so as to understand the main idea on the thinking of the Yi learning from Yao Pei-Chung