《隋书·经籍志》与《新唐书·艺文志》是古籍目录史上很有成就的四分法目录。本文通过比较两者在分类编目上的不同,例如小类的增减、小类名称的变化、子目的有无及部分小类收书的情况等,来探究四部分类法从唐初至北宋中期发生的一些变化。 “Sui Shu Jing Ji Zhi” and “New Tang Shu Yi Wen Zhi” is a tremendous achievements in the history of ancient books directory of four points. In this paper, by comparing the two in the classification of the different catalogs, such as minor changes, changes in the name of the sub-category, the sub-sub-category and some sub-closed books, etc., to explore the four categories from the early Tang Dynasty to the mid-Northern Song Dynasty Some changes have taken place.