The relaxor ferroelectric (RFE) behavior in high-energy electron-irradiated poly(vinylidene fluoride-trifluoroethylene) [P(VI)F-TrFE)]80/20 mol % copolymer system is characterized over a broad frequency and temperature range. The dielectric properties remarkably vary with the irradiated dose in terms of the change from normal ferroelectric (FE) to RFE phase. During the RFE-paraelectric (PE) transition, the dielectric constants, as a function of temperature, can be described by the Vogel-Fulcher (V-F) relation. It has been found that the relationship between the real and imaginary part of dielectric constant in irradiated copolymer can be well fitted with modified Cole-Cole equation and Debye relaxation equation, exhibiting similar features as inorganic RFES. (c) 2005 Wiley Periodicals, Inc.