A display device for compensating for degradation of a threshold voltage of a driving thin-film transistor (“TFT”) and method for driving the display device includes a light-emitting element, wherein the light-emitting element emits light by a driving current applied thereto, a driving TFT controlling the magnitude of the driving current directed to the light-emitting element, a capacitor which charges a voltage which varies depending on a data voltage and a threshold voltage of the driving TFT and maintains a voltage corresponding to a difference between the data voltage and a gate voltage of the driving TFT, a first switching unit supplying the data voltage to the capacitor in response to a scan signal, and a second switching unit which is diode-connected and supplies the driving TFT with a light emitting signal.