Li Si (about 284 BC and 208 BC), named Si, had the courtesy name Tonggu. At the end of the Warring States Period, he was a native of Shangcai, State of Chu. A famous politician, writer and calligrapher in the Qin Dynasty. The greatest contribution of Li Si, the prime minister of the Qin Dynasty, to calligraphy was the creation of the small seal script, also known as "Qin seal script", based on the large seal script (bronze inscriptions). After Qin Shihuang unified the characters, Qin seal script became the official script of the Qin State.

As a court lieutenant, he was ordered to discuss the title of "Emperor" with Prime Minister Wang Wan, Imperial Censor Feng Jie and others. He later served as prime minister and accompanied the First Emperor on many tours. He opposed Chunyu Yue's proposal to enfeoff his children, and advocated the ban on private learning and the abolition of "Poems", "Books", Historical Records of the Six Kingdoms and "Hundred Schools of Language".

Played a major role in King Qin's cause of destroying the six countries. After Qin unified the world, he agreed with Wang Wan and Feng Jie to respect Qin Wangzheng as the emperor and formulated relevant etiquette systems. Was appointed prime minister. He suggested demolishing county walls and destroying civilian weapons; he opposed the enfeoffment system and insisted on the system of counties and counties; he also advocated burning folk collections of "Poetry", "Books" and other hundreds of languages ????and prohibiting private study in order to strengthen centralized rule. The county system was an improvement over the feudal system and was conducive to the unification of the country.

At this time, he had the opportunity to get close to the King of Qin Yingzheng, and persuaded the King of Qin to take the opportunity to defeat the six countries and unify the world. He was promoted to Changshi by King Qin Yingzheng, and later to Keqing. He advocated the abolition of the "Expulsion Order" and was adopted by the King of Qin. Li Si was promoted to Tingwei. As for Si, he had ambitions and had ambitions in his heart to implement. Seeing that Qin is so much stronger than the six countries. When he found the opportunity, he persuaded King Qin to take the opportunity to attack the six countries. What a great achievement.

Li Si immediately told Qin Wangzheng his unification plan. One was to destroy South Korea first, and then use the "disturbance strategy" to drive a wedge between the six countries. The meaning of the divorce plan is to use money to drive a wedge between the six eastern countries, even if they cannot make them enemies of each other. Li Si analyzed for Qin Shihuang that the reason why the country had become strong since Qin Mugong, but could not finally unite the six kingdoms, was that the vassal states were still numerous and Zhou's virtue had not declined.

However, since Qin Xiaogong, the Zhou Dynasty has declined and the princes have merged with each other.