During Qin period (from 221 BC to 206 BC), China came into unification for the first time and under reign of the first emperor Qin Shihuang. Its government seated in Xianyang (close to modern Xi'an). Although Qin Dynasty survived for only 15 years, it had exerted such great influence on the following dynasties that it held an important role in Chinese history. Many administrative institutions were developed at that period and have remained features of the Chinese state for the following 2000 years.

Qin emphasized strict adherence to a legal code and the absolute power of the emperor. Qin emperor contributed much to the development of his country by launching a series of effective measures, including the concept of a centralized government, the unification of the legal code, written language, measurement, and currency of China.

Despite of Qin emperor's contributions to the country, he was more of a tyrant. In order to silence the criticism of the imperial rule, he burnt many books that he thought would affect people's thinking and even worse, he buried 460 scholars alive after learning about their discussion of his cruelty.

At the same time, in order to build luxurious palaces, Terracotta Warriors and Horses, the Great Wall and his own mausoleum, the emperor imposed heavy taxes, hard labor, military service and rigorous law on the masses.