An apparatus and method for providing preferred contents to a user in an Internet broadcasting system that provides a broadcast service using an Internet data transport protocol. A user terminal sends a request for a broadcast service to a service provider. The user terminal receives an authentication key from the service provider, and delivers the authentication key to a third display terminal in which a user of the user terminal is not registered. The third display terminal delivers the authentication key and connection information of the third display terminal to the service provider. The service provider authenticates the third display terminal. The user terminal transmits information selected by the user to the service provider, which transmits broadcast service data related to the selected information to the third display terminal for being displayed.