Yun Tieqiao is a well-known educator in China and a firm supporter of Chinese medicine. He believes that people who study medicine need to understand the "Book of Changes", and "Book of Changes" and "Internal Classics" have many similar views.For example, the theory of yin and yang and the change of the four seasons will have a huge impact on the world. Based on these, Yun Tieqiao proposed the "Four Seasons and Five Elements Theory" and the "Four Seasons and Five Internal Organs".At the same time, the "Book of Changes" and "Internal Classics" also have differences. The "Book of Changes" talks about ghosts and gods, while the "Internal Classics" does not mention ghosts and gods; the "Internal Classics" talks about the Five elements and Jiazi, while the "Books of Changes" does not mention Five elements and Jiazi.