Later, Huai Su came to Chang 'an to further study calligraphy. Wei Li, the official minister, saw that his calligraphy was greatly appreciated and thought that he had a bright future. He said, "This Saman Zahan is a great name in the universe." Huai Su felt that his calligraphy was not taught by a teacher, so he took Cao, the Emperor of the Jin Dynasty, as a teacher and learned brushwork. Huai Su also had many contacts with the great calligrapher Yan Zhenqing. They learn from each other, discuss with each other, and deepen their understanding of brushwork.
Huai Su is absorbed in calligraphy and has a good understanding. One night, watching the summer clouds move with the wind, unpredictable. "I realized the brushwork and called myself cursive." He is famous for cursive script in the world, especially Weeds, and is called "a snake in a storm" by critics. Literatis at that time, such as Li Bai and Dai Shulun, all wrote poems praising his Wild Grass. Li Bai's Cursive Song said: "The teenager is called Huai Su, and the cursive script is called the best in the world." Say his words, "the wind and rain are rustling, the falling flowers and snow are boundless ... when you smell ghosts and gods, you always see dragons and snakes go far;" The left side of the plate is like a shock, like a struggle between Chu and Han. " Prior to this, Zhang Xu's cursive script was famous in the Tang Dynasty and was called "Zhang Dian"; People thought that Huai Su's calligraphy inherited Zhang Xu's brushwork and developed, so later people called him "crazy" and called him and Zhang Xu "drunkards". The main works are Preface and Postscript, Thousand Words Grass and so on, among which Preface and Postscript is the most representative.
The origin of Preface is as follows: In the seventh year of Dali (772), Huai Su went north to Chang 'an and Luoyang to seek further development. Because of his free and easy personality and excellent cursive script, he was greatly appreciated by calligraphers, poets and celebrities such as Yan Zhenqing, who presented poems in succession. In the twelfth year of Dali (777), I extracted some poems and preface and wrote this post in Weeds. The preface almost sums up the main deeds of his life. At the same time, the highest artistic achievement in life is also reflected in the hearty pen and ink. Autobiographical Notes is his masterpiece, with 702 words in 126 lines and composed of 15 pieces of paper. This post is written in big letters with a fine pen, and the strokes turn and escape, such as winding a steel cable; The pen tip is like a hook, so-called "iron pen silver hook" is also. The whole volume emphasizes the continuous grass trend, turning up and down with the pen, swinging left and right, fast, light and heavy, like rhythmic music, very dynamic. In addition, there are scattered strokes, which emphasize the ambiguity and endless brushwork, the tip of the pen is hooked back, and the strokes echo each other between words and lines. The whole picture changes strangely in the rules and regulations, and the expression is surging, which is the ultimate expression of cursive art. In the Ming Dynasty, An Qi called this post "the colors of ink, air and paper are wonderful and moving, and the vertical and horizontal changes occurred at the beginning, which is mysterious."