To achieve high performance in molecularly dispersed photorefractive polymers, it is essential for the sample films to show the large electro-optic: coefficient (r(33)), which is emerged by orientating nonlinear optic (NLO) molecules incorporated toward the external electric field applied across the film. In this work, the effect of casting temperature in preparing the sample films was examined. It was found that the samples prepared by casting at the higher temperature showed the larger r(33). In the samples thus prepared, the diffraction efficiency and response in FWM experiments were much improved.