Abstract: An in-cell touch display panel includes a plurality of first sensing electrodes, a pixel matrix, a plurality of second sensing electrodes, a touch control unit, and a display driving unit. The plurality of first sensing electrodes are for generating touch sensing signals according to touch scanning signals. The plurality of second sensing electrodes are utilized as common voltage electrodes of pixels of the pixel matrix. Wherein when the display driving unit drives pixels of a first block of the pixel matrix to display image, the display driving unit outputs a common voltage to the pixels of the first block via the second sensing electrodes corresponding to the first block, and outputs the touch scanning signals via the second sensing electrodes corresponding to a second block of the pixel matrix; and wherein the display driving unit switches a frequency of the touch scanning signals according to magnitude of a noise.