It has been known that the chalcone dimerizes efficiently. We modified BPDA-PDA (poly(surface with sulfuric acid and aqueous KOH solution. The modified surface provides the binding sites for photo-ractive materials. A chalcone derivative has been synthesized, which possesses reactive functional group to the modified surface. The synthesis of the chalcone derivative was confirmed. The photoreactions of the chalcone derivative were followed by UV-visible spectroscopy. The isomerization occurs with irradiation of UV light and Finishes in 5 min. Succeedingly the photo-dimerization occurs.