A liquid crystal display (LCD) with a built-in touch screen includes: a first substrate including a pixel area having a plurality of pixels and a sensor area having a plurality of photosensors; a second substrate positioned over the first substrate, and including a color filter, a light receiving portion, a transparent electrode layer, and a front polarizing plate; an LCD panel including a liquid crystal layer interposed between the first and second substrates; and a touch screen driver circuit to sense a capacitance variation provided through a first sensing line connected to the transparent electrode layer when an object is in contact with the LCD panel, and to output position information of the object, sensed by using optical information sensed through a second sensing line connected the plurality of photosensors when the capacitance variation is greater than or equal to a predetermined threshold value.