1 closed to the outside world: closed to the outside world and not in contact with foreign countries. Strictly restrict foreign economic, cultural and scientific exchanges. Although the closed-door policy has a certain self-defense function against the invasion of western colonialists in a certain period of time, it can not weaken the strength of western capitalist countries, but hinders their own development, which makes China lose the initiative of foreign trade, cuts off the scientific and technological exchanges between China and foreign countries, hinders the development of productive forces and social progress, widens the gap between China and the West, and creates a passive situation in modern China.

2 Authoritarian centralization: in feudal society, the throne is lifelong and hereditary. The emperor is the supreme power of the country, and he is arbitrary from decision-making to the exercise of military, political and financial power. Centralization is relative to decentralization, which is characterized by the fact that local governments have no independence in politics, economy and military affairs, and must strictly obey the orders of the central authorities and obey everything. Both local government and central government must obey the emperor. When autocratic imperial power is strengthened, centralization is often more effective, and when autocratic imperial power is weakened, centralization is often weak. Emperor Xiaowen's reform in the Northern Wei Dynasty: Emperor Xiaowen of the Northern Wei Dynasty issued a decree of land equalization in 485, and officially moved the capital to Luoyang in 495, ordering Xianbei nobles to sinicize and adopt the political system of the Han ruling class. These reforms accelerated the feudal process of the northern ethnic minorities at that time and promoted the great integration of the northern ethnic groups. 4 Well-field system: Well-field system is the state-owned system of ancient land in China, which prevailed in the Western Zhou Dynasty. At that time, roads and passages crisscrossed, dividing the land into "well"-shaped squares, so it was called "ore field". The mining field belongs to the king of Zhou and is distributed to the people. The Lord can not buy or sell, not transfer the mine field, but also pay a certain tribute. The Lord forced the people to collectively cultivate the mine field, surrounded by private fields and in the middle by public fields. Well field system is a land exploitation system under slavery. Well field system is essentially a private land system.