A digital TV system and a method for supporting a film mode in a digital TV system include generating an original frame from two fields except for repeated fields among 60 fields inputted in an interlaced scanning method if the film mode is detected, and converting the generated frames into 60 frames of a progressive scanning type by repeatedly outputting the generated frames three times or twice by a specified rule, setting an input audio signal to match the film mode in consideration of the number of speakers provided in the digital TV and the number of channels of the input audio signal, and displaying an icon for indicating the film mode on a predetermined position of a TV screen. Thus, a viewer can view the film with a higher picture quality and with reality through the DTV.