After Ping and Dong Wang moved to the capital, the royal family weakened, the doctors of the later countries merged with each other, and the strong factions appeared one after another, breaking the situation that the clans coexisted and the imperial court dominated. In the process of merger, the old system of the Western Zhou Dynasty was gradually destroyed, especially the change from hereditary and non-tradable clan land ownership to family land ownership, which became the most basic change in the social changes of the Eastern Zhou Dynasty. Clans have occupied a lot of land since the Western Zhou Dynasty. This land ownership system takes feudal exploitation as its content, clan organization as its shell, and patriarchal clan system is the owner of clan-owned land. The clan of Hou paid tribute to the princes and served as various corvees. They were sometimes punished by the governors, given double gifts, and sometimes expelled or even extinct. When clans become powerful and rulers lose or weaken their control, clan merger becomes popular. The strong clan won the land and set up local officials to manage the civil affairs, but it did not prevent the reappearance of the new clan by enfeoffment of children. The clan party that lost the clan lost the protection of the clan and also got rid of the wealth of the clan. Under the condition that local officials are obliged to pay tribute, a family becomes an independent economic unit. Parents have the right to dispose of their own property, forming a family system with parents as the main body. The family system replaced the clan system, that is, the family-based land ownership replaced the clan-based land ownership. A family will become a landlord if it occupies more land, and a farmer if it occupies less land or cultivates other people's fields. Both landlords and farmers should establish a family system in which parents are the masters. The content of the family system is that children obey their fathers and brothers, and women obey men, sons and daughters-in-law. They are not allowed to own private property, dare not borrow other people's property privately, and dare not give it to others privately. Everything is controlled by parents. After the death of parents, brothers can live in different houses, and every man may participate in social activities as a parent, so the old country based on clan system will gradually become a new country based on family system. During the Western Zhou Dynasty and the mid-Qin and Han Dynasties, the Eastern Zhou Dynasty and the Warring States Period were both carrying out the alternating movement of these two kinds of rule, and the Eastern Zhou Dynasty was the beginning of this movement.