A method of displaying a digital broadcasting signal using a digital broadcasting receiver and a digital display device is disclosed. In the present invention, information on a display mode of the display device is communicated to the digital broadcasting receiver through a bi-directional communication line. As a result, the digital broadcasting receiver can process the input digital broadcasting signal according to the display mode. Thus, the digital broadcasting signal can be displayed in an optimum display mode through the digital display device. Accordingly, the received digital broadcasting signal can be displayed in diverse formats and in an optimum condition.