In the history of calligraphy, he is the most accomplished and influential calligrapher after the two kings. His book was first learned in Zhang Xu's four years in the early Tang Dynasty. Later, it was widely collected and learned, changed the ancient method, opposed the calligraphy style of the early Tang Dynasty, and used the pen of seal script to make it thin and hard, with a broad structure and magnificent momentum. This style also embodies the style of the prosperous Tang Dynasty and conforms to his noble personality, which is the beauty of calligraphy. His calligraphy style is called "Yan Ti", which is also called "Yan Liu" with Liu Gongquan, and has the reputation of "Yan Liu Jin Gu". It is said that there are 138 kinds of his works. Regular script includes "Many Pagodas and Monuments" and "The Story of Magu Xiantan". Among them, it is very personalized, such as "Jing Qing presses the sword, Fan Kuai holds the shield, King Kong looks at his eyes, and Lux punches." There are several cursive scripts, such as Sacrifice to My Nephew, Contention for Seats, Pei Jun Post and Confessions. Among them, offering sacrifices to nephews is the highest artistic realm in a very sad mood, and it is called "the second running script in the world". Mi Fei's Book History: "The book of seats is very powerful, and it is the first of Yan's books. The characters are connected, flying strangely and unexpectedly."