A backlight unit having a polarization film for performing the function of a reflective polarization film, wherein the backlight unit includes a light source, an optical film and a polarization film. The light source emits a light having a certain wavelength, the optical film is located proximate to the light source to transmit the light outputted from the light guiding plate in a certain direction, and the polarization film is located proximate to the optical film. Here, the polarization film has a UV curing resin and lines disposed on the UV curing resin, and polarizes the light transmitted from the optical film. The backlight unit manufactures the polarization film by using an UV curing resin and a metal substance, and thus the manufacture period of the polarization film may be reduced enabling the polarization film to be manufactured in great quantities.