Photo-reactive polymers based on poly(vinyl cinnamate) were prepared and characterized to investigate the optical properties which could be applicable to alignment layer in liquid crystal devices. Alkoxy chains or fluorine is successively attached to the cinnamoyl chromophore matrix as a LC-director subject to linearly polarized ultra-violet irradiation. Cross-links generated by polarized light produce (2+2) cycloaddition between cinnamoyl groups and induce photo-polymerization aligning LC molecules on the polymer layer. The anisotropic photo-orientation behaviors of poly(vinyl cinnamate) derivatives are affected by the chemical nature of substituents at the end group of the side chain.