Photosensitive pre-polymer monomers are mixed together with nematic liquid crystal in certain ratio. Then the mixture is injected into the cells for liquid crystal. The surfaces of the cells are coated with alignment films and rubbed for anti-paralleled alignment. Phase separation between liquid crystal and pre-polymer monomers takes place when ultraviolet light is applied with the shielding plate covering on the cells, which results in the formation of liquid crystal/polymer phase grating. Since the liquid crystal rotates 180° along the cell surfaces with the effect of alignment films, the disadvantage of traditional liquid crystal grating depending on the polarizing direction of incident light is overcome, and the utilization efficiency of light is improved. The samples are checked up by optical microscope and He-Ne laser. The results indicate that the samples have clear grating structure, their diffraction efficiencies do not change with the polarizing directions of the incident lights and can be modulated by electric field. The PDLC gratings with low driving voltage could be fabricated easily. They show numerous potential applications including optical communication devices, diffractive optical elements, projection displays and light valve.