A document management system includes a primary storage server and a secondary storage server. The primary storage server stores document information about a document including owner information for identifying a user having registered the document and group information for identifying a group to which the user belongs in the primary storage server storage device for each group based on the group information included in the document information. The secondary storage server specifies the group information for identifying the group to which the user accessing the document belongs, acquires the document information about the specified group information, and then stores the acquired document information in the secondary storage server storage device for each user based on the information about the user accessing the document.