Organic-inorganic hybrid films having organic NLO chromophore with large hyperpolarizability were prepared by the sol-gel processing method. Their linear and non-linear optical properties, thermal stabilities, and poling efficiency were investigated. The macroscopic second-order non-linearity in the hybrid films was established by the corona poling method and were strongly depend on poling conditions such as poling temperature, poling time and heating rate. The optimized d(33) values in resulting films exhibited 50-58 pm V-l from the maker-fringe measurement. It was found that the thermal stabilities of NLO activities were greatly enhanced when poling time increased and poling temperature became higher. (C) 2001 Elsevier Science B.V. All rights reserved.