PURPOSE: To display a message at a message displaying device with a different form by transmitting routine message including a message identifier and an address identifier with a returning side computer, and using a displaying form identifier registered according to the form of a message displaying device and executing the editing with a receiving side computer.

CONSTITUTION: When a message to be transmitted to a computer Ca occurs at a computer Cb, a message transmitting means 1b transmits an address identifier, a message identifier and variable information d1, d2...dn necessary to the message to the computer Ca. A message displaying means 2 of the computer Ca compares the address identifier and address identifiers #1, #2...#n of an address-classified displaying form table 3, finds the coincident identifier and determines a displaying form identifier corresponding to the address identifier. Next, the message displaying means 2 edits and determines the displaying message from a message table 4 based on the displaying form identifier, the message identifier of a transferring message and the variable information d1, d2...dn.