This study was to examine the operation strategy of terrestrial broadcasting system on channel image and N-screen service. Nowadays, terrestrial broadcasting system provides video streaming service based on internet. In other words, terrestrial broadcasting system provides N-screen service through TV-PC-Smart phone-Tablet PC. But it is different for terrestrial broadcasting system to analysis the choice criterion of program. Only, channel image of terrestrial broadcasting system expanded into N-screen. Finally, channel image of terrestrial broadcasting system is the competition strategy. It is necessary for terrestrial broadcasting system to prepare the strategy of program choice for users, original contents, new platform and service in connection with N-screen.