The present disclosure provides A touch sensing system comprising: a display panel having pixels and touch sensors; a display driving circuit that writes data to the pixels; a touch sensing part that senses touch input; a plurality of multiplexers that connect one of sensor lines connected to the touch sensing part; and a touch sensor controller that performs full sensing to detect a multiplexer with a sensed touch input by supplying a driving signal to the touch sensors within the touch sensing periods, performs pre-sensing to determine whether or not a touch input is sensed in multiplexers adjacent to the multiplexer with a sensed touch input, and performs local sensing to scan the touch sensors connected to the multiplexer with a sensed touch input based on the pre-sensing result and to calculate the coordinates of the touch input.