The Great Learning, The Doctrine of the Mean, The Analects of Confucius and Mencius are all called the four books, which are the basic teaching materials of Confucianism. For hundreds of years, the "Four Books" have been widely circulated in China, and many of them have become popular aphorisms. The Four Books refer to The Analects of Confucius, Mencius, The Doctrine of the Mean and The University. Among them, The Analects of Confucius and Mencius are collections of speeches by Confucius, Mencius and their students respectively, while Daxue and The Doctrine of the Mean are two books in The Book of Rites. Zhu, a famous scholar in the Southern Song Dynasty, first linked the two. However, before Zhu, Cheng Hao and Cheng Yi had strongly advocated these books. They believe that "University" is an important work taught by Confucius, which was compiled by Ceng Zi. The Doctrine of the Mean is a book "Confucius teaches the mind", and it is a pen, which is written by Confucius' grandson Zisi. Together with The Analects of Confucius and Mencius, these two books express the basic ideology of Confucianism and are the most important documents for studying and treating Confucianism. It is from this perspective that Zhu compiled four books: The Analects of Confucius, Mencius, University and The Doctrine of the Mean. Because they came from four representatives of early Confucianism, namely, Confucius, Zeng Shen, Zi Si and Mencius, they were called "Four Books" for short. Zhu annotated the four books respectively. Among them, the annotations of Daxue and the Doctrine of the Mean are called "chapters and sentences", and the annotations of The Analects and Mencius are called "concentrated notes" because they quote many other people's sayings. It is worth noting that the order of Zhu's four books was originally The University, The Analects of Confucius, Mencius and The Doctrine of the Mean, which was arranged in the order of learning from the shallow to the deep. Later generations put The Doctrine of the Mean before The Analects of Confucius because the length of Daxue and The Doctrine of the Mean was short. In order to facilitate printing and publishing, it became the order of Daxue, The Doctrine of the Mean, The Analects of Confucius and Mencius that prevailed the previous year. Because Zhu Zhu's "Four Books" not only combines the theories of predecessors, but also has its own unique views, which are applicable to the world; Due to the rising status of "Zhu Cheng Neo-Confucianism" represented by Cheng Hao, Cheng Yi brothers and Zhu, after Zhu's death, the court approved four books with his annotations as official books, which became popular from then on, and resumed the imperial examination in the Yanyou period of the Yuan Dynasty (13 14- 1320), officially. Due to these factors, the Four Books not only became important classics of Confucianism, but also became a must-read for every reader and became a unified standard primary school textbook until modern times. Therefore, some people compare the four books with the Western Bible and think that they are the Eastern Bible. In fact, whether it is its widespread spread or its profound influence on the character and psychology of China people, this comparison is not an exaggeration.