Because of the development of IPTV, user is provided service of multimedia data regardless the location. But the number of users who try to get service of IPTV game illegally is also increasing. In this paper, user authentication protocol in IPTV housing using PIN code not to access easily for teenagers not to access to prohibited games. The proposed protocol combines authority data in IPTV household and creates a disposable password using PIN code to prevent teenagers from accessing illegally to the prohibited games and saves the data in certification server and set-top box to prevent forced accessing.