Semiconductorlike CaCu3Ti4O12 ceramic powders are filled into a poly(vinylidene fluoride-trifluoroethylene) copolymer matrix to form a flexible composite. The dielectric constant of the composites at 100 Hz reaches more than 600 at room temperature and 1200 at 70 degrees C, as shown in the figure. The contribution of the heterogeneous relaxation is partially responsible for the high dielectric constant observed here.