Disclosed are system and method for providing an advertisement service using the call-connecting signal in the server of a common carrier. The method includes receiving a call request signal from the originator terminal, extracting an advertisement message from the advertisement database, and sending the advertisement message to the originator terminal. Also, the method further includes interrupting sending of the advertisement message if a call is connected between the originator terminal and the recipient terminal, extracting further commercial data related with the advertisement message, and sending the extracted further data to the originator terminal.