A method for providing a notification message in a transmitter of a mobile broadcast system supporting an interaction channel is disclosed. Upon an occurrence of a notification event, a first means generates a notification message, and generates at least one delivery request message including a target address based on subscription information of the corresponding terminal, using the generated notification message. A second means determines a channel over which it will deliver a notification message to the corresponding terminal based on the target address, and delivers the notification message over the determined channel.