When describing the history of Emperor Taizong, Zi Tong Zhi Jian often used "going to Vietnam" to record a large number of Li Shimin's short famous sayings about governing the country, such as the well-known "water can carry a boat, but it can also overturn it" and "you can dress with copper as a mirror; Take people as a mirror and know the gains and losses; Taking the ancient as a mirror can be replaced by Xiao Xing ". After reading these words of wisdom, I can't help wondering, why didn't you publish the Quotations of Li at that time? Later, after reading it, I realized that no one had put forward such a suggestion at that time, not only quotations, but also several volumes of Li Shimin's collected works. Emperor Taizong is not only famous for his martial arts, but also for his excellent poems. The Complete Poems of Tang Dynasty contains many of his magnificent and beautiful poems. He highly praised Xun Yue's "Han Ji" and recommended it to Minister Li Daliang and others. It is no exaggeration to say that he is a great strategist, writer, poet and historian. As for his calligraphy style, there is no information at present, but judging from his love for Wang Xizhi's Lanting posts and his final burial in Zhaoling, he is at least a calligraphy enthusiast. In view of this, in Zhenguan 12, Zuo Shilong requested to compile the Collected Works of the Emperor, but it was declined by Taizong. The reason is: "My words are beneficial to the people, and history is written and immortal. If it's useless, what's the use of collecting! Liang Wudi, his son Chen Houzhu and Emperor Yang Di all collected works. How can I save myself from death? What is the article? " This excuse is a crown, but I don't believe it. I'm always skeptical of politicians' words, especially those big words. I think there must be something else in the collection. After the death of Emperor Taizong, Emperor Gaozong acceded to the throne. It is said that "Li Shimin funeral committee" and "Zhaoling Management Office" proposed to set up a "Complete Works Compilation Committee of Wu Wen and Sheng Di" to compile and edit the Complete Works of Li Shiming (1-5), and this work has already started. Due to the complexity of the project, it was not completed in the year of "Long Live the Sky" in Wuzhou. At that time, Li was replaced by Wu, and Wu Zetian satirized that several ministers called for the restoration of the Complete Works of Shimin. Naturally, she approved it quickly, because Taizong himself was quoted above. The reason why Wu Zetian banned the publication of the Complete Works of Li Shimin is understandable, but the real intention of Emperor Taizong's refusal to publish his collected works has not been clarified. This is the question I left when I read Zi Tong Zhi Jian and Tang Xin Shu more than 20 years ago. Later, I was lucky enough to meet several experts and scholars specializing in Tang Shi and ask them for advice. Unfortunately, most of them are vague and hard to convince. Recently, however, I occasionally read the Yearbook of Literary Studies in the Tang Dynasty, and one of them, An Examination of Du Fu's Death written by a famous historian, inspired me. I seem to find the clues that Emperor Taizong refused to publish the Selected Works. This immortal article explores the hidden truth, and demonstrates in detail whether Du died after eating beef or drinking buffalo. These have nothing to do with this article, so I won't copy and paste them. However, it can be seen that the night scene in Du Zimei is bleak. "But there is no news from relatives or friends, I am old and sick, and I am alone with my boat." I should die of poverty and illness. This conveys a message that in the prosperous Tang Dynasty, the works of Du Shaoling, a poet, were famous all over the world, but there was no stable source of income. Therefore, it is concluded that there was no imperial power system in the Tang Dynasty, let alone imperial power. No wonder Du Fu's life is so tight! This conclusion has been proved circumstantially in other famous works that study the literature of the Tang Dynasty, such as An Examination of Tang People's Writings. From this, can we speculate like this?