X-ray radiation-induced structural changes in the semicrystalline random copolymer poly(vinylidene fluoride- co-trifluoroethylene) (70-30) film were studied by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, ultraviolet/visible and infrared absorption spectroscopies and Raman scattering. The X-ray diffraction shows a decreasing degree of crystallinity with increasing X-ray irradiation times. The differential scanning calorimetry experiments show that the ferroelectric transition temperature T c and the melting temperature T m are lowered under X-ray irradiation. Thermogravimetric analysis shows one step weight loss with a decreasing decomposition temperature and increasing amount of residue with increasing irradiation times. The UV/vis spectra of irradiated copolymer film show the appearance of absorptions at ~192, 222, 272, 342 and 364 nm related to CC<, diene, triene and chromophores of radical ion species, respectively. Infrared spectra show a small high wavenumber shift for bands associated to CH stretching vibrations, decreasing intensities at 1293 and 852cm −1 and the appearance of new bands at 1847, 1750 and 1717cm −1, that increase in intensity with irradiation times. Raman spectra show an increasing fluorescence contribution with increase of irradiation time. A decreasing intensity of bands at 847 and 884cm −1 could be related to decreasing degree of crystallinity of the copolymer film. The X-ray irradiated P(VDF-TrFE) (70-30) films show physical and chemical change consisting in diminished degree of crystallinity, loss of ferroelectric property and the formation of new chemical structures (CC<, diene, triene and chromophores of radical ion species).