The influence of the crystallization condition - temperature and time - on the structure of poly (vinylidene fluoride chlorotrifluoroethylene), P(VDF-CTFE), was studied using DSC and XRD. The DSC results of all studied polymers show three peaks. One peak, which is associated with crystallization temperature, represents the appearance of unstable phase in the polymers. Both XRD and DSC data indicate the coexistence of different phases in the polymers, which may be the reason for the high electrostrictive performance obtained in the polymers.