An EPD device includes a plurality of pixels, wherein a first pixel is written by a first grey level, a second pixel is written by a second grey level. When the EPD device refreshes the displayed frame, the first pixel and the second pixel are erased individually. After the erasing of first pixel is completed, a third grey level is written to the first pixel immediately. After erasing of the second pixel is completed, a fourth grey level is written to the second pixel immediately. Thus, each pixel is written by their next grey levels immediately after the erasing step so the writing time is reduced and the motion blur of the EPD device when refreshing the displayed frame can be improved.