Huai Su (737~799), an outstanding calligrapher in the Tang Dynasty, was known as "Cao Sheng" in history. The word Cang Zhen, the monk's name is Huai Su, and the common surname is Qian. He is a native of Lingling, Yongzhou (Lingling, Hunan) and the nephew of Qian Qi, one of the ten gifted scholars in Dali.
He became a monk at an early age, and after meditation, he devoted himself to cursive writing, just like Zhang Xu. Collectively called "Dian Zhang Kuang Cao", it formed the coexistence of two peaks of calligraphy in the Tang Dynasty, and it was also the two peaks in the history of cursive writing in China. Huai Su's cursive script is thin and vigorous, flying naturally, like a whirlwind of showers. Calligraphy is ever-changing, ever-changing and has statutes. Professor Peking University and pioneer Li Zhimin commented: "Huai Su's cursive script has a delicate and graceful god in the escape and an innocent spirit in the wild."
Handed down from ancient times, calligraphy works include autobiographical posts, thousands of words on grass, bitter bamboo shoots, Notre Dame posts, essays on books and so on.