A nanocomposite with enhanced dielectric response is developed using poly(vinylidene fluoricle-trifluoroethylene) [P(VDF-TrFE)] as matrix and Chemically modified high dielectric constant organic semiconcluctor-copper phthalocyanine oligomer (CuPc)-as filler. Transmission electron microscope (TEM)-observed morphologies reveal that in the nanocomposite the average size of CuPc particles is about 25 nm [1/24 of that of CuPc in physical blend of P(VDF-TrFE) and CuPc]. The hot-press nanocomposite film with 15 wt % CuPc can realize a dielectric constant of 540 at 100 Hz. The enhanced dielectric response in the nanocomposite demonstrates the significance of the inter-face effect in raising the material responses far beyond that expected by simple mixing rules when there is a large dielectric contrast between the polymer matrix and the dielectric filler in the composite. It is also interesting to note that at high frequencies (such as 100 MHz) the nanocomposite has a dielectric constant of similar to 100 and this value is comparable to those of current materials used in microwave applications. At 105 degrees C that is near the ferroelectric-to-paraelectric phase transition temperature of the P(VDF-TrFE) ferroelectric, a much higher dielectric constant (about 1200 at 100Hz) is obtained. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 490-495, 2010