A privilege information management system configured to: store a group tree configured with group nodes each representing a group configured with a member enabled to use a privilege; store an object tree configured with object nodes each representing a target object to be used with a privilege; store, in a releasable manner, privilege-valid link information indicating a connection between an arbitrary group node of the group nodes and an arbitrary object node of the object nodes in a privilege-valid mode; and regarding a first group node of the group nodes and a first object node of the object nodes connected by the privilege-valid link information, grant a privilege to use a target object of the first object node and a subordinate object node if there are any under the first object node to a member belonging to the first group node and a subordinate group node if there are any under the first group node, wherein the privilege information management system is configured to: store, in a releasable manner, privilege-invalid link information indicating a connection between an arbitrary group node of the group nodes and an arbitrary object node of the object nodes in a privilege-invalid mode; regarding a second group node of the group nodes and a second object node of the object nodes connected by the privilege-invalid link information, not grant a privilege to use a target object of the second object node and a subordinate object node if there are any under the second object node to a member belonging to the second group node and a subordinate group node if there are any under the second group node; and determine, on the basis of link information existing on a shortest route having a minimum number of links among a plurality of routes for connecting the group node and the object node in an overlapping relation with respect to granting of a use privilege and non-granting of a use privilege, whether to grant a privilege to use a target object of the object node in the overlapping relation and a subordinate object node if there are any under the object node to a member belonging to the group node in the overlapping relation and a subordinate group node if there are any under the group node. store a group tree configured with group nodes each representing a group configured with a member enabled to use a privilege; store an object tree configured with object nodes each representing a target object to be used with a privilege; store, in a releasable manner, privilege-valid link information indicating a connection between an arbitrary group node of the group nodes and an arbitrary object node of the object nodes in a privilege-valid mode; and regarding a first group node of the group nodes and a first object node of the object nodes connected by the privilege-valid link information, grant a privilege to use a target object of the first object node and a subordinate object node if there are any under the first object node to a member belonging to the first group node and a subordinate group node if there are any under the first group node, store, in a releasable manner, privilege-invalid link information indicating a connection between an arbitrary group node of the group nodes and an arbitrary object node of the object nodes in a privilege-invalid mode; regarding a second group node of the group nodes and a second object node of the object nodes connected by the privilege-invalid link information, not grant a privilege to use a target object of the second object node and a subordinate object node if there are any under the second object node to a member belonging to the second group node and a subordinate group node if there are any under the second group node; and determine, on the basis of link information existing on a shortest route having a minimum number of links among a plurality of routes for connecting the group node and the object node in an overlapping relation with respect to granting of a use privilege and non-granting of a use privilege, whether to grant a privilege to use a target object of the object node in the overlapping relation and a subordinate object node if there are any under the object node to a member belonging to the group node in the overlapping relation and a subordinate group node if there are any under the group node.