The relationship between Confucius and The Book of Songs is closely linked. According to historical records, there were more than 3,000 original "The Book of Songs", and only 305 were left after being revised by Confucius. Confucius attached great importance to the function of poetry. He said that poetry can enlighten people's minds, and etiquette system can regulate people's words and deeds. Of course, learning poetry can not only help people to stimulate their imagination, but also observe things, know groups and express their grievances. It is because of his evaluation of poetry that he became the earliest literary critic. Later, Confucius strongly recommended and advocated reading The Book of Songs. He also asked his son Kong Li if he had studied the Book of Songs. Kong Li said no, and Confucius said: If you don't study poetry, you have nothing to say. It can be seen that Confucius attached importance to the Book of Songs.
Regarding its evaluation, Confucius once said: Confucius speaks politely, and poetry, books and rituals are polite. He thinks that The Book of Songs, The Book of Classics and How to Observe the Etiquette System are all elegant words. On the other hand, Confucius praised the language of The Book of Songs and thought it was elegant and civilized. As for the poem Guan Ju in The Book of Songs, Confucius thinks its style is peaceful and just right. Confucius has always advocated the doctrine of the mean, and it should be very high to have such an evaluation of Guan Yu.