The thermal stability of thin DR1/PMMA, DR1/silica, and DRS/silica systems was studied by UV spectroscopy. DRS which can covalently bind with reactive silica was synthesized between 4-[ethyl(2-hydroxyethyl) amino]-4’-nitro azobenzene (disperse red 1, DR1) and 3-isocyanatopropyl triethoxy silane. The characterization of chemicals and incorporated films were carried out by UV/VIS spectroscopy, DTA, H-1- and C-13-NMR, and FT-IR. After poling of DR1 and DRS incorporated at various temperatures, the UV absorbance decreased due to the alignment of DR1 and DRS by electric field. The second harmonic generation response was obtained by using Nd:YAG laser. The thermal stability of DRS and DRS/silica system was enhanced, compared to that of DR1 and DR1/silica system, respectively.