Multi bi-layered film hav ing optical periodicity with different refractive indices has been studied for one dimensional photonic crystals (1DPC) showing photonic band gap (PBG) in which the existence of a certain energy range of photons is forbidden. In this study, we synthesized copolymer consisting of azobenzene and mesogen which has no absorbance i n ultraviolet region, and multi bi-layered film with the copolymer and polyvinyl alchol was prepared on a glass substrate by spin coating. Optical properties of the multi bi-layered film were investigated.