Digital Teletext is one of the most important interactive services of emerging digital television. As an enhanced version of existing analogue Teletext service, it's a resident application of the set-top box. Its information will be stored in a data carousel and transmitted via broadcasting network. The new service can display smooth graphics and images, have page links and a menu driven navigation method. However, there is no standard specification available for the content format. This paper presents a content format based on Extensible Markup Language (XML). A prototype of digital Teletext system is implemented using the Java programming language.