The research work of The Book of Songs is called Confucius Book for short, with a total of 40 volumes. In the 16th year of Zhenguan in Tang Dynasty (642), Justice, one of the Five Classics written by Confucius (574 ~ 648), was an official book issued at that time. Kong, a native, was born in Hengshui, Jizhou (now Hebei). He worked as a doctor, a secretary and a wine sacrifice in the countryside. At that time, the Five Classics of Justice was written by Kong, who was in charge of it because of his seniority. Once Confucianism was divided and ruled, the justice of Mao's poems was written by Wang Deshao and others, and Confucius always succeeded. The Justice of Mao Poetry is the reconciliation of Mao Zhuan and Jian Zheng. Biography and Jian Zheng are called annotations, and justice is called sparseness. Together, they are called Annotations on Mao Shi and General Catalogue of Sikuquanshu, saying: "Liu Zhuo's works are based on Mao Shi Yi Shu and Liu Xuan's works. It contains various interpretations of the Book of Songs by scholars in the Han and Wei Dynasties, and brings together the achievements of scholars in the Jin, Southern and Northern Dynasties. Some places can put forward some new ideas, such as expressing doubts about Confucius' theory of deleting the Book of Songs in Historical Records, but his books follow the principle of "sparse without breaking notes" and fail to surpass Mao Zhuan and Jian Zheng. In terms of reconciliation, this book is full of superfluous words, which is also the same shortcoming of the generosity of the Tang people.
The popular version of Justice of Mao Poems is Notes to Thirteen Classics, among which Justice of Mao Poems by Ruan Yuan is the best, followed by a collating draft of Justice of Mao Poems by Ruan Yuan.