A generation unit general monitor-control system for generally monitoring and controlling electric power generation units (A-3 etc.), the general monitor-control system allocating relations between the electric power generation units and interface devices (11) for monitoring and controlling the generation units. The monitor-control system includes: a unit database (13) storing process data and operation signals; process input-output means (14) for reading out the data from this unit database and outputting the data to the generation units; unit database input-output portion (12) for receiving demands from the interface devices, detecting addresses of the generation units allotted to the interface devices, and referring to data corresponding to the addresses; interface device designating means (22) for designating interface devices; and an interface-device-unit-relation rewriting device (18) for rewriting the allocation relation between the generation unit and the interface devices based upon command from the interface device designating means.