In one aspect, a wallpaper alignment apparatus may include a first alignment unit and a second alignment unit. In one embodiment, each of the first and second alignment units is detachably disposed and aligned with the edge of the wallpaper through an adhesive. The first alignment unit has a first elongated main body and a plurality of protrusions extending from the first elongated main body. The second alignment unit has a second elongated main body and a plurality of recesses formed on the second elongated main body to receive corresponding protrusions on the first alignment unit to further align the wallpapers.