Du Du was born in Duling, Jingzhao, Eastern Han Dynasty. The word Bodu. It is said that his original name was Cao, but people in the Wei and Jin Dynasties changed his name to Du Du because they avoided the taboo of Emperor Wu's name. The great-grandson of Du Yannian, the imperial censor, was the prime minister during the reign of Emperor Zhang of Han Dynasty. Du Du is famous for his good Zhangcao. Cui Yuan and Cui Shi's father and son studied Du Du's calligraphy, and later generations were called "Cui and Du" and they were Zhang Zhishi. Zhang Zhi and Zhu Cishu. He claims to be "superior to Cui and Du". Wei Dan from the Wei Dynasty during the Three Kingdoms period commented: Du Shijie has strong bones but is thin in calligraphy and painting. He is like a frost forest with no leaves, and a waterfall of water flying in and out. "Jin Weiheng's "Four Styles of Calligraphy" says: "Qi Prime Minister Dudu is good at cursive calligraphy. His character "sha" is very safe but his calligraphy is thin. "Liang Yu Jianwu of the Southern Dynasty listed Du Du's Zhang Cao as a divine product in his "Shu Pin". Zhang Huaiguan of the Tang Dynasty listed Du Du's Zhang Cao as a divine product, commenting: "Although Shi You Shi Cao was not recorded in the book biography. It's possible, but it's impossible. The only person who created it was Du Gong. " He also compared Zhang Zhi and Du Du and said: "Bo Ying (Zhang Zhi) lost or lost Bo Du Zhangcao, just like Yi Shao increased or decreased Yuan Chang's real calligraphy. Although the polishing is good at cutting, the meaning is beautiful. As for the profound meaning and the quality of the wind, they are not as good as the master. "The book "Shu Duan" says: "Du Du was good at cursive writing and was known as Emperor Zhang. His deeds were valued highly and he was ordered to write in cursive script. "Comments" in the second volume of "Shu Duan" says: "Du Caogai has no masters, and he is full of spiritual changes. He is the standard for future generations. This is the natural number one." "Also said: "Zhangcao is ancient and elegant, extremely profound, and Zebodu is the first. "Tang Weixu's "Mo Sou·Nine Grades of Calligraphy" lists Du Duzhang's cursive script as the best.