A data management system is provided for managing data stored in a plurality of image forming apparatuses. In the data management system, a network communication section of a first complex machine requests a second complex machine to transmit attribute information indicative of data stored on a HDD of the second machine, and storage location information for specifying the second machine and for specifying a storage location of the data in the HDD. A network communication section of the second machine responds to the request by transmitting the attribute information and the storage location information thereof to the first machine. The network communication section of the first machine receives the information transmitted from the second machine. A table-data creation section of the first machine then creates table data for correlating information received by the network communication section thereof and stores the created table data on a HDD thereof.