A decoration panel the length of which is adjustable so that it may be fitted to a various sizes of walls, windows, furniture and so on. The decoration panel includes a main panel having a plurality of holes aligned on the upper or lower part of it in the vertical direction. Sub panels having a front cover and a plurality of holes on the rear of the front cover corresponding in spacing to the holes are inserted on the upper or lower end of the main panel. A joiner is engaged through the holes of the sub panel into the holes of the main panel.