士族是北朝重要的社会阶层,在政治、经济、文化方面都承担着关键性角色。北魏孝文帝末年,以魏晋旧籍并当世仕宦为依据,确立了卢、崔、郑、王、李五姓之地位~①,此后这五姓经营婚宦,社会声望日隆,成为北方第一流门第。从宗族构成看,北朝士族多数在汉代便已形成郡望,至曹魏西晋渐次凝成,由于宗族发展,郡望下复分成多个房支,至北魏中叶以后虽泛称郡望,却实以房支为单位 The tribe is an important social class in the North and plays a key role in political, economic and cultural fields. In the last years of the Northern Wei Dynasty Xiaoguang Dynasty, the status of Lu, Cui, Zheng, Wang and Li Wu was established on the basis of the Wei and Jin dynasties and on the basis of Shi Shi Huan. Thereafter, these five surnames were engaged in marriage and social prestige, First-class door. From the composition of the clan, most of the Bei dynasty nobles in the Han Dynasty have formed a county look, to Wei Wei Xi Jin gradually concerted, due to the development of the clan, the county is divided into a number of house branches under the county, although after the middle of the Northern Wei Dynasty, generally known as the county look, Branch as a unit