A document access control system for determining whether to allow a client to access a target document file according to a security policy set in a server, the system includes a cache timing determination part for determining the timing for caching policy determination data corresponding to the target document file in the client, a policy determination data obtaining part for obtaining the policy determination data from the server according to a report from the cache timing determination part, a policy determination data storage part for storing the obtained policy determination data in correspondence with the target document file, and a file access control part for controlling access to the target document file according to the policy determination data stored in the policy determination data storage part in a case where the user of the client requests access to the target document file when the client is in an offline mode.