A method of driving a light emitting display device comprising a display panel including M subpixels (SP, SP1-SP4), wherein the subpixels (SP, SP1-SP4) each have a driving transistor, an organic light-emitting diode (OLED), wherein a first electrode of the driving transistor is connected to a power line (EVDD) and a second electrode of the driving transistor is connected to the anode of the organic light emitting diode (OLED), and a sensing transistor having a second electrode thereof connected to the anode of the organic light-emitting diode (OLED) for acquiring a sensing value therethrough, and wherein the subpixels (SP, SP1-SP4) share one single sensing line (VREF1) that is connected to a first electrode of the sensing transistor of each of the subpixels (SP, SP1-SP4), wherein M is an integer equal to or greater than 2, the method comprising: in an initial period, applying an initialization voltage to the anode of the organic light-emitting diode (OLED) included in the M subpixels (SP, SP1-SP4) through the sensing line (VREF1); in a data writing period, applying a sensing voltage to a gate of the driving transistor included in a sensing subpixel from among the M subpixels (SP, SP1-SP4) and applying a non-sensing voltage to gates of the driving transistors included in the other of the M subpixels (SP, SP1-SP4) which are non-sensing subpixels (SP2-SP4), wherein the non-sensing voltage is set to a black voltage at which the organic light-emitting diode (OLED) included in the non-sensing subpixel does not emit light; and in a sensing period, sensing the at least one characteristic of the organic light-emitting diode (OLED) included in the sensing subpixel through the sensing line (VREF1), wherein the initial period is longer than the data writing period, wherein the sensing voltage is set to a voltage level at which the organic light-emitting diode (OLED) included in the sensing subpixel emits light, and wherein the initialization voltage is set to a voltage level at which the organic light-emitting diode (OLED) included in the non-sensing subpixels (SP2-SP4) does not emit light. in an initial period, applying an initialization voltage to the anode of the organic light-emitting diode (OLED) included in the M subpixels (SP, SP1-SP4) through the sensing line (VREF1); in a data writing period, applying a sensing voltage to a gate of the driving transistor included in a sensing subpixel from among the M subpixels (SP, SP1-SP4) and applying a non-sensing voltage to gates of the driving transistors included in the other of the M subpixels (SP, SP1-SP4) which are non-sensing subpixels (SP2-SP4), wherein the non-sensing voltage is set to a black voltage at which the organic light-emitting diode (OLED) included in the non-sensing subpixel does not emit light; and in a sensing period, sensing the at least one characteristic of the organic light-emitting diode (OLED) included in the sensing subpixel through the sensing line (VREF1), wherein the initial period is longer than the data writing period, wherein the sensing voltage is set to a voltage level at which the organic light-emitting diode (OLED) included in the sensing subpixel emits light, and wherein the initialization voltage is set to a voltage level at which the organic light-emitting diode (OLED) included in the non-sensing subpixels (SP2-SP4) does not emit light.