Zhang Xu (675-750) was born in Wu (now Suzhou, Jiangsu) in the Tang Dynasty, and his ancestral home was. Changshu county magistrate Zeng Guan and the long history of Jin Wu. Good cursive script, good wine, known as the world Zhang Dian, is also one of the "eight immortals drinking." At that time, his cursive script, together with Li Bai's poems and Pei's dance, was called the "Three Wonders", and his poems were unique and good at the Seven Wonders. The Eight Immortals with Li Bai, He and others. Tang Wenzong once wrote a letter, regarding Li Bai's poems, Pei Min's sword dance and Zhang Xu's cursive script as "three unique skills". History is called "the sage of grass".
Zhang Xu also taught Yan Zhenqing calligraphy.