The Na/Bentonite Polyaniline (Na/Bent-PANI) nanocomposites were synthesized by the intercalation of aniline monomer into interlayer of cation exchanged with bentonite, followed by in situ intercalative polymerization method in which clay and aniline were used in different amounts. From FTIR spectra of the nanocomposite characteristic vibration modes of both Na/Bent and PANI were confirmed. X-Ray Diffraction (XRD) results indicate that the intercalation of polyaniline into interlayer spacings of silicate layers of Na/Bent and the polymerization occurs mainly between the clay layers. Dielectric properties were studied of this nanocomposites in the 0.1-30 KHz frequency range and at 282-383 K temperature interval. The maximum interaction between PANI and clay was observed at high temperature and low frequencies. The change of relative permittivity and dielectric losses versus frequency indicates the electrode polarization besides ionic conductivity. A sudden increase was shown as the amount of aniline (ml) increased as well as a dielectric conductivity increase at high temperatures. This was due to the electrical communication between polymer stacks.