PURPOSE: To reduce the load of a host computer to be generated at the control of the communication processor and to improve the maintenance in the computer system having communication processors.

CONSTITUTION: The computer system is mainly constructed by a host computer, communication processor 1-1, and terminal groups 1-9 to be connected with the host computer. The system consists of a local host control section 1-5 operating as if the host computer is in the communication processor, path control section 1-4 controlling the destination of the communication data from the connected terminals to the host computer or to the local host control section, and processing result output section 1-7 controlling the destination of the output result. Thus, the required information can be obtained without fail at the fault generation. Further, the remote control can be attained by means of terminals connected to the host computer.