Disclosed is a method for setting virtual volume groups in a storage network system. The system includes a lower storage apparatus, host computers, an upper storage apparatus, and an administrative server. The method for setting virtual volume groups, executed by the administrative server, includes the steps of acquiring information on the real volumes, and port information on the physical devices in which the real volumes reside, creating virtual volumes being linked to the real volumes, based on the information on the real volumes, forming one or more virtual volume groups by combining the virtual volumes, based on the port information, in such a way that a relation between the virtual volumes and the virtual volume group are identical to a relation between the real volumes and the physical devices, and establishing the created virtual volume groups in the upper storage apparatus.