PURPOSE: To provide an inexpensive system for commanding and controlling public peace maintenance and disaster prevention capable of quickly and surely dealing with a disaster in a plant, etc., provided in a wide site.

CONSTITUTION: The system is provided with plural site condition recognizing means 4, 5 or 6 for recognizing the various conditions of a site, a center device 1 and a movable sub-center device 3 for executing a prescribed public peace maintenance and disaster prevention processing based on plural detecting signals from the respective site condition recognizing means 4, 5 or 6 and branching parts 8 in plural places. The system consists of a coaxial cable 7 with which the site condition recognizing means 4, 5 or 6, the center device 1 and the movable sub-center device 3 are connected to the branching parts 8 and the movable sub-center device 3 can be connected to any of the branching parts 8.