The present invention relates to a display device capable of reducing power consumption and preventing flicker, as well as a driving method thereof. An exemplary display device includes: a display panel configured for display of a still image and a motion picture; a signal controller programmed to transmit control signals for driving the display panel; and a graphic processing unit transmitting input image data to the signal controller. The signal controller includes a frame memory storing the input image data, and the display panel is driven at a first frequency when the motion picture is displayed and alternatingly driven at the first frequency and a second frequency when the still image is displayed, the second frequency being lower than the first frequency.