Abstract: This invention relates to an inner-page structure of a document file, mainly comprising a plurality of inner pages which may be document bags or bags for receiving optical disks etc. A projecting rib is provided at one side of the inner pages with respect to a retaining seat of the document file. The projecting rib has an engaging portion provided on the outer end for engagement with a groove of the retaining seat when the projecting rib is fittingly inserted into the groove of the retaining seat. In this manner, the inner page can be directly fixed with the retaining seat so as to enhance the entire operation performance.