A touch sensor integrated display device comprising: a display panel with a plurality of pixels, each pixel comprising an organic light emitting diode (OLED), a driving thin film transistor for applying a source-drain current to the organic light emitting diode (OLED), whereby the driving thin film transistor and the organic light emitting diode (OLED) are coupled in series with each other between a high-potential driving voltage (EVDD) and a low-potential driving voltage (EVSS), a first switching thin film transistor configured to switch on an electrical connection between a data line and a gate node (Ng) of the driving thin film transistor in response to a scan control signal (SCAN) from a first gate line, a second switching thin film transistor configured to switch on an electrical connection between a sensing line and a source node (Ns) of the driving thin film transistor in response to a sensing control signal from a second gate line, and a storage capacitor (Cst) connected between the gate node (Ng) of the driving thin film transistor and the source node (Ns) of the driving thin film transistor; a gate drive circuit configured to generate the scan control signal (SCAN) and the sensing control signal and to supply the scan control signal (SCAN) and the sensing control signal to gate lines (15A, 15B) of the display panel; a data drive circuit configured to set a gate-source voltage to turn on the driving thin film transistor by applying a data voltage (Vdata) for touch sensing to a gate node (Ng) of the driving thin film transistor through the data line and a reference voltage (Vref) to a source node (Ns) of the driving thin film transistor through the sensing line, during a reset period based on the scan control signal (SCAN) and the sensing control signal, and to output a sensing value obtained through the sensing line by sensing a change in the source-drain current of the driving thin film transistor caused by touch input, during a sensing period subsequent to the reset period; and a timing controller configured to compare the sensing value with a predetermined reference value to detect the touch input. a display panel with a plurality of pixels, each pixel comprising an organic light emitting diode (OLED), a driving thin film transistor for applying a source-drain current to the organic light emitting diode (OLED), whereby the driving thin film transistor and the organic light emitting diode (OLED) are coupled in series with each other between a high-potential driving voltage (EVDD) and a low-potential driving voltage (EVSS), a first switching thin film transistor configured to switch on an electrical connection between a data line and a gate node (Ng) of the driving thin film transistor in response to a scan control signal (SCAN) from a first gate line, a second switching thin film transistor configured to switch on an electrical connection between a sensing line and a source node (Ns) of the driving thin film transistor in response to a sensing control signal from a second gate line, and a storage capacitor (Cst) connected between the gate node (Ng) of the driving thin film transistor and the source node (Ns) of the driving thin film transistor; a gate drive circuit configured to generate the scan control signal (SCAN) and the sensing control signal and to supply the scan control signal (SCAN) and the sensing control signal to gate lines (15A, 15B) of the display panel; a data drive circuit configured to set a gate-source voltage to turn on the driving thin film transistor by applying a data voltage (Vdata) for touch sensing to a gate node (Ng) of the driving thin film transistor through the data line and a reference voltage (Vref) to a source node (Ns) of the driving thin film transistor through the sensing line, during a reset period based on the scan control signal (SCAN) and the sensing control signal, and to output a sensing value obtained through the sensing line by sensing a change in the source-drain current of the driving thin film transistor caused by touch input, during a sensing period subsequent to the reset period; and a timing controller configured to compare the sensing value with a predetermined reference value to detect the touch input.