The NASICON system Na4.7+xTi1.3-x(PO4)(3.3-x) is synthesized for 0.0 <= x <= 0.6 and investigated the electrical properties in wide range of frequency and temperature. By means of nonlinear least square fitting of appropriate equivalent circuits, the bulk conductivity is separated from electrode effects. Ac conductivity and permittivity data are analyzed by using conductivity formalism. The dc conductivity and hopping frequency activation energies are found to be in the range of 0.56-0.64 eV. The hopping frequency activation energy is in agreement to the activation energy of dc conductivity. The scaling behavior in ac conductivity is studied and observed that the ion dynamics is independent of temperature and composition. (c) 2005 Elsevier B.V. All rights reserved.