Multichannel on digital TV not only gave opportunities to the TV audience to view a wide range of programs. but also made it difficult for them to search for the program which they plan to view among over 1000 programs broadcasted on more than 100 channels. In this paper the functions of EPG (Electronic Program Guides) required by the users on digital TV were derived from the systematic analysis of multichannel viewing situations. In the situation analysis the situations where they viewed programs on more than 100 channels were generated systematically and the viewing processes in those situations were analyzed to identify user needs and derive the required functions of EPG. We surveyed the viewing behavior of the audience who subscribed to a digital satellite broadcast. SkyPerfecTV. in Tokyo. Japan. The purpose of the survey was to verify the validity of the functions derived from the situation analysis and to identify hidden user needs which were difficult to in the situation analysis. The functions were implemented on a working prototype of EPG based on a digital TV simulator which broadcasts 500 programs on 100 channels and can be controlled by three working prototypes of personal remote controllers. The working prototype will be used in Participatory Design to make it possible for the users to experience and verify the usefulness of the required functions of EPG and also find problems in user interface design of EPG