Han inherited the Qin system: In 200 BC, Liu Bang adopted Lou Jing's suggestion and moved the capital to Chang 'an. Lou Jing thinks that Liu Bang won the world differently from the previous Zhou Dynasty, so Luoyang should not be the capital like the Zhou Dynasty, but the capital of Guanzhong. Sean and others also suggested moving the capital to Guanzhong, because Guanzhong is a land of victory, with a large population and rich products, which is conducive to Qin Zhen's defensive position and the country's prosperity. Lou Jing named Wei Liu a surname, and Liu took "Feng Chunjun" as a doctor, and later served as a Shanhaiguan Hou. After Liu Bang proclaimed himself emperor, he attached great importance to the lessons of Qin's death. He ordered scholar Lu Jia to summarize the experience and lessons of the rise and fall of dynasties including Qin Dynasty for reference. Lu Jia believes that it is not that Qin Shihuang did not want to govern the country well, but that the measures formulated were too cruel and the punishment was too cruel, so the State of Qin perished. Your majesty has the world, and if you want the country to be stable for a long time, you must use both the army and the people. This is the "long skill". Liu bang agrees with this very much. Liu Bang believes that another important factor in the demise of the Qin Dynasty is that the policies adopted by Qin Shihuang were too harsh and urgent, especially on the issue of canceling the "enfeoffment system", which affected nearly a thousand years. If it is to be abolished, the people can't accept it immediately, and the opposition is too loud. Liu Bang believes that the enfeoffment system is still an important means to eliminate opposing feelings and stabilize princes. At the same time, Liu Bang did not want to see the division of feudal lords and the hegemony of the pack. The county system established by Qin Shihuang is an effective measure to overcome this shortcoming. Therefore, Liu Bang adopted a parallel method of county system and enfeoffment system, which is called "county-state parallel system". After learning the experience and lessons of Qin's death, the Han Dynasty inherited most of the systems of the Qin Dynasty. Different from the cruelty of criminal law and the strictness of governing the country, the guiding ideology of governing the country in the Han Dynasty was pure and inaction, which was reflected in the economic aspect of tax reduction for the people. The political system of the Han Dynasty is basically a continuation of the Qin Dynasty, with three officials and nine ministers at the central level and a county system at the local level. However, the local institutions at the township level in the Han Dynasty are different from those in the Qin Dynasty, that is, one of the three elders in each township is elected as the three elders in the county, responsible for contacting county-level officials and communicating the relationship between superiors and subordinates. In addition to the county system, the Han Dynasty also implemented the feudal system, that is, enfeoffment of princes and kings, and the establishment of vassal States and kingdoms in the local area. Han Xin and other kings with different surnames were originally enfeoffed, mainly to unite the people to win the war. At the beginning of the Han Dynasty, seven kings with different surnames were enfeoffed. Later, except Wu Rui, the king of Changsha, they were all eliminated one after another. However, in the process of flattening the king with different surnames, Gaozu enfeoffed nine kings with the same surnames, all of whom were Gaozu's sons, nephews and brothers. Emperor Gaozu stipulated that the political status of vassal states was equal to that of counties, and the central government sent Guo Xiang to assist vassal kings. Guo Xiang, an official of the central government, is not allowed to collude with the vassal king against the central government, otherwise he will be punished as a felony of "Albania attaching interest". At the same time, there is Hou Guo, whose status is equal to that of counties, mainly for the founding of the people's Republic of China. In this way, vassal States and counties coexist, because the kingdom and vassal States have their own independent judicial power, which caused the confusion of local political mechanisms later. In order to maintain the hierarchy, Gaozu also followed the Qin's twenty-level title system. On the basis of Qin Law, Gaozu also reformed a new law, namely the famous Nine Chapters of Han Dynasty. While making laws, Gaozu followed the example of Qin Dynasty and established a set of etiquette system. To sum up, the system of inheriting Qin from Han Dynasty is embodied in the system of etiquette and law. There are many differences between Liu Bang, the emperor gaozu of Han Dynasty, and the ruling policies of Qin Dynasty, which are summarized, formulated and implemented by drawing lessons from the experience of the demise of Qin Dynasty. In short, through the above series of measures, a unified centralized feudal empire was re-established. Due to the eight-year war, the population of the Han Dynasty at the beginning of the founding of the People's Republic of China dropped sharply and the economy was depressed. In order to promote economic prosperity and development, Emperor Gaozu ordered the release of prisoners, the repatriation of refugees, the demobilization of soldiers, the liberation of handmaiden and the encouragement of childbearing. At the same time, he adjusted the land policy and developed the agricultural economy. In order to arouse farmers' enthusiasm for production, on the basis of the Qin tax system, Gaozu adopted the policy of being frivolous and thin. In addition to frivolous taxes, Gaozu also mobilized the enthusiasm of farmers by means of "conferring titles" and "restoring titles". Not only did he pay attention to the development of agricultural production, but Emperor Gaozu also adjusted the industrial and commercial policies. The main measure is to relax the restrictions on private industry and commerce, which not only revitalizes industry and commerce, but also promotes agricultural production. Korea inherited the feudal state organization of Qin system.