The influence of azo-dye molecular structure, especially of the terminal substituents on the photo-induced anisotropic properties of their films was investigated. In order to avoid the solubility of azo-dyes in liquid crystals (LC), their sodium salts were synthesised. The photoinduced anisotropic properties were studied both as individual substances and as mixtures with polyamide acid (PAA). The pretilt angles of nematic liquid crystals oriented by photoanisotropic films of azo-dye with PAA were measured.