Under the feudal system, there was a strict hierarchy from the common people to the emperor. If the lower class wants to enter the upper class or the ruling class, it must pass the selection, which developed into the imperial examination in Sui and Tang Dynasties. The Records of the Arts and Literature of Han Dynasty contains: "Han Xing, Xiao He said in a rough way:' Those who can satirize more than 9,000 books in the Imperial Examination will be history. "In addition, the six-body examination is used, and the most important courses are minister history, suggestion history, history books and history books. The government and the people wrote a letter, and it was disintegrated when the words were not correct. In addition, Ma Zonghuo said in the Book of the Woods that he attached great importance to calligraphy in the Tang Dynasty: "Take books as teaching to imitate Zhou, take scholars from books to imitate Han, and set doctors from books to imitate gold." The study of calligraphy began in the Tang Dynasty. "Since the Tang Dynasty, calligraphy has played an increasingly important role in the selection. Therefore, scholars all over the world are committed to this, and the brush is in a dominant position in the field of ancient writing tools. The imperial examination and practical purpose promoted the popularization and improvement of calligraphy, which not only trained generations of calligraphers, but also produced countless calligraphy critics and appreciators.