seal script is one of the ancient scripts of Chinese characters, also called seal script. Is a general term for ancient Chinese characters. "The seal maker, who spreads it, spreads its physics, and applies it endlessly." The ancients thought that seal script was made by Cang Xie, but it is not credible. The generation of a kind of writing takes a long process of development, and it is impossible for a person to complete it in a short period of time. Generally speaking, seal script includes all scripts before Lishu and their extended genera, such as inscriptions on bronze, Shi Guwen, ancient prose of Six Kingdoms, small seal script, Miao seal script and overlapping seal script. Narrow sense mainly refers to "Da Zhuan" and "Xiao Zhuan". The characters of seal script are rounded, and the structure is in accordance with the meaning of the six books, so Sun Guoting in Tang Dynasty said, "Seal script is graceful and fluent".