There are provided a display device, driving method and sensing unit thereof, where a display device includes a display unit having pixels connected to signal lines; a sensing unit including at least one current sensor connected to at least one of the signal lines; and a compensator connected between the sensing unit and the display unit, wherein the compensator is configured to: calculate degradation weights for positions of the pixels, based on a sensing current measured by the sensing unit and a predetermined reference current value, update degradation accumulated values for the positions whenever the sensing current is measured, by accumulating degradation degrees in which the degradation weights are reflected, generate compensated grayscale values by compensating input grayscale values based on the updated degradation accumulated values, and output the compensated grayscale values to the pixels.