Embodiments of the present disclosure relate to a display device including a display panel having a plurality of gate lines extending in a first direction, a plurality of data lines extending in a second direction, and a plurality of subpixels; a gate driving circuit for supplying scan signals to the plurality of gate lines; a data driving circuit for supplying data voltages to the plurality of data lines and including a sensing circuit of characteristic value to sense the characteristic value of the plurality of subpixels; and a timing controller for controlling the gate driving circuit and the data driving circuit, and determining a defective line by detecting a distorted section for the sensed characteristic value for each subpixel arranged in the second direction in respect to a plurality of blocks corresponding to the display panel.