After Qin Shihuang unified China (22 1 year ago), Xiao Zhuan implemented the policy of "writing is similar, cars are on the same track", and Prime Minister Li Si was responsible for the unified measurement. On the basis of Zhou, which was originally used in Qin State, Xiao Zhuan simplified it, canceled the variant characters of other six countries, and created a unified Chinese writing form. China characters developed to the stage of Xiao seal script, and gradually began to finalize the design (outline, strokes and structure), which weakened the pictographic meaning, made the characters more symbolic, and reduced the confusion and difficulties in writing and human reading. This is also the product of the first large-scale use of administrative means to standardize writing in the history of China. The Qin Dynasty unified the national characters with the sorted seal script, which not only basically eliminated the phenomenon of different lines of characters in different places, but also greatly changed the situation of different fonts in ancient Chinese, and played an important role in the development history of China characters.