Apparatus for inserting watermark and method therefor

There are provided an apparatus for inserting a watermark and a method therefor. The apparatus for inserting a watermark includes a watermark pattern image receiving unit that stores a watermark pattern image including a preset bit value; a watermark information generation unit that stores watermark information including binary tracking information generated based on at least one of a user ID value and a terminal ID value; and a watermark insertion unit that receives watermark pattern images corresponding to bit values of the stored watermark information from the watermark pattern image generation unit, and overlays the watermark pattern images in sequence on a display screen.