During the Wei, Jin, Southern and Northern Dynasties, some families in the landlord class enjoyed political and economic privileges and constituted a special class. The continuation of the development of aristocratic families in the Eastern Han Dynasty is the origin of aristocratic families. The policy of the ruling class in Wei and Jin Dynasties was the direct cause of the formation of the gentry class. The nine products of Cao Wei are the main conditions for the establishment of family status, which makes the official career of the children of the dynasty prosperous; Wei and Wu generals gave the officials of the Western Jin Dynasty and their vassals the right to occupy the land according to their official property, allowing the dignitaries to widely occupy the land, tenants and handmaiden. Therefore, the gentry in Wei and Jin Dynasties must be the dignitaries of the dynasty, and only those families who gained political status in Wei and Jin Dynasties, especially those who gained political status in Wei and Jin Dynasties, are eligible to be listed as gentry. For example, the evil king and king in Wei and Jin Dynasties moved to Taichang, Situ, Taiwei and Taibao; Yu is in Yingchuan. Yu is Wei's domestic servant. He is an ordinary domestic servant in Jin. Chen's family is Wei Diannong's corps commander, and Jpua is Jin's drink offering. The Eastern Jin Dynasty was the heyday of the development of the gentry. The Eastern Jin regime was established with the planning and support of Wang Dao and Wang Dun of the Wang family. Therefore, as the saying goes, "The king and the horse share the world" (Biography of Wang Dun in the Book of Jin). Later, Ying Chuanyu, Qiao Guohuan, Chen Junxie and other aristocratic families took turns to be in power, forming a game between jade and horse, Huan and horse, and Xie and horse. At this time, the aristocratic forces were parallel to or even surpassed the imperial power, and the imperial power politics evolved into the door-door politics. In order to protect their own interests, the gentry compiled genealogy, prohibited intermarriage with non-gentry and refused to associate with them. During the Liu and Song Dynasties in the Southern Dynasties, Didang and Zhou Fang, two calligraphers from poor backgrounds, were in charge of important affairs. They once visited the gentry Zhang Fu and begged him to move to a distant place without contact. Small officials of the gentry who don't do complicated dramas, that is, the so-called "turbid officials", flaunt their aristocratic families. After the Eastern Jin Dynasty, the boundary between the gentry and the poor was basically solidified, and only a few poor families could rise to the status of the gentry. However, the gentry were also divided in their development. For example, the family status of Cui Shi in Qinghe was higher than that of Cui Shi in Boling, and the family status of the descendants of the evil king was also different. The gentry in the Southern Dynasties gradually declined. Due to the suppression of imperial power, although senior officials are granted no real power; Due to the increasing corruption of the gentry, the sons and daughters of the gentry "don't get on the bus, but the secretary (lang) is in the body". They are born rich, don't think about making progress, indulge in debauchery and extravagance, and even "smoke clothes and shave, make powder and give it to Zhu" (Yan Zhitui's "Yan Family Training Mianxue"). The Hou Jing Rebellion resulted in the death of the gentry in the Southern Dynasties. In order to consolidate his rule, Emperor Xiaowen of the Northern Wei Dynasty formulated a strict system of gentry, which divided the gentry into four grades according to their official positions and enjoyed political and economic privileges according to their grades. The gentry system was customarily formed in the Wei, Jin and Southern Dynasties, but it was stipulated by the court in the form of law in the Northern Wei Dynasty. The gentry in the Northern Wei Dynasty also became corrupt rapidly and suffered a heavy blow in the change of Yin He.