唐代前期(安史之亂以前)為中古門第社會的一個階段，自有其一貫相承的同質性格，譬如「士庶區別」士庶之見猶然深入人心，特別是門第世族每好標榜郡望，以示其門第崇高，自矜兼也矜人，蔚為風尚。本文研究主旨，即以郡望問題為中心，探討唐代前期門第世族的郡望與寒族、蕃姓偽冒姓望的現象，藉以窺探中古門第社會性格的一斑。

Pre-T’ang Dynasty (before An-Shi rebellion) is the social stage of family status in the Middle Ages. It has a consistent inherit on the same characteristics. For example, there are differences between learned person and general person. The point of view between these two stages has deeply affection on people’s minds, especially paraded on the prominent family status of learned person. It becomes the taste of the time whatever restrained or be restrained. The main points of this research paper is focus on the kep of nobles family, studying about the nobles and poor families, the phenomenon of conterfeit of foreign name, so as to look inside the nobles family’s social characteristics during the Middle Ages.