Duota Monument was written by Yan Zhenqing, a calligrapher in Tang Dynasty, in the 11th year of Tianbao, which reflected his early calligraphy style. The font is neat and meticulous, the structure is rigorous, and the pen is meticulous, so this monument is also the most popular model for future generations to learn regular script. The inscription inherited the legacy of the "two kings" in Europe, Henan and Chu, showing a kind of rigor and solemnity. In terms of brushwork, Fang Bi mostly uses a round pen.
Yan Zhenqing's regular script is characterized by correct writing attitude, rigorous font structure, rounded strokes and vigorous strokes.