Zhang Xu benefited from Chu Suiliang, especially his understanding of the law of Tibetan front. He saw from the hidden front in Chu Suiliang's works that the root of Chu Suiliang's vigorous Gu Zhuo lies in the hidden front. And the pen in the center makes the line features more obvious. Inspired by Zhu Suiliang, Zhang Xu made the brushwork of the center freely shaped and expressed in the prosperous Tang Dynasty. His skillful use is the first person to express his temperament in calligraphy.
Zhang Xu played an irreplaceable role in the prosperity of calligraphy art in Tang Dynasty, especially in the development of cursive script. Zhang Xu's later Huai Su, Gao Xian and others inherited Zhang Xu's grass method, strengthened the power of weeds, and further expanded Zhang Xu's understanding and careful observation of nature.
Yan Zhenqing was not only one of Zhang Xu's most accomplished disciples, but also learned from Zhang Xu in Xia Yunguan and House Leak, which opened a new way of thinking for political reform. Wu Tong, Cui Miao and others also made great achievements by studying under Zhang Xu, and they are more influential figures among Zhang Xu's disciples. Zhang Xu is not only a peak in the history of China's calligraphy, but also has an immeasurable influence on later generations.