PURPOSE: To provide a repeating system which eliminates the need for correcting operation on a server machine even when a new application program(AP) is added to a host computer.

CONSTITUTION: An application program(AP) 3a of a work station(WS) 3 transfers a message to an AP 1a on the host computer 1a through a host repeating process 10 provided to the server machine 2 irrespectively of the APs. Therefore, even when a new AP is added, the process on the server machine 2 is unchanged and the correcting operation is not necessary. Namely, the message outputted from an AP 3a on the WS 3 and the address of the host computer 1 are stored in a message area by an interface module 11 provided to the WS 3, the host repeating process 10 is decided as the transmission destination, and the host repeating process 10 generates new message data to be sent to the host computer 1 on the basis of the address stored in the message area.