An active matrix type liquid crystal display device driving method for switching a partial display mode and a normal display mode. The respective data lines of the partial display area are scanned in a certain period defined as a frame period, "k" pieces (symbol "k" is integer larger than, or equal to 1) of the partial display areas are present within 1 screen, a common electrode potential is varied 2k times within 1 frame period; a common electrode potential in a partially scanning period for scanning the partial display area is made as a constant potential against a reference of a driving circuit for driving the data lines; and within at least two continued frames, a common electrode potential of a blank period other than the partially scanning period is made as a constant potential which is different from the constant potential in the partially scanning period.