Novel Ag-BaTiO3/PVDF (polyvinylidene fluoride) three-component nanocomposites and traditional BaTiO3/PVDF two-component nanocomposites were prepared by the same procedures. The dielectric properties of these two kinds of composites were compared. The results showed that the kind of three-component nanocomposites had better dielectric properties. The energy density of such kind of composites could reach nearly 10 J/cm(3), which indicated that these nanocomposites could be used as the dielectric layers of pulse-power capacitors. The Coulomb blockade effect was used to explain the dielectric breakdown properties and the resistivities under high electric field of such new kind of nanocomposites. (C) 2008 Elsevier B.V. All rights reserved.