Based on the matching data of China's industrial enterprise database and China customs database from 2000 to 2011,this paper discusses the impact of intermediate input import on enterprise's markup from the perspective of import diversity. The results show that the increase of import diversity of intermediate input is conducive to the increase of markup of non-technical frontier enterprises, but it has a restraining effect on the markup of technology frontier enterprises. The agglomeration of enterprises in the same location and industry is helpful to expand the extensive margin of import diversity of technology frontier enterprises, thus increasing the markup. Under the constraints of the same location and industry, the technology frontier enterprises that both import and export and the technology frontier enterprises in the eastern region can benefit from the “spillover effect” of enterprise agglomeration, and increase the markup by increasing the diversity of enterprises' imports.