The dielectric properties of pure PVC and pure PVC filled composites were performed to examine and characterize the structure of polymer composites. At room temperature the values of relative permittivity, loss factor, and ac conductivities were calculated as a function of frequency and it was found that incorporation of both micro and nano PbO and CuO with various wt% to the polymer matrix resulted in enhanced dielectric properties. The electrical response of polymer matrix micro- or nanocomposites show their conductivity and dielectric behavior. So the principal electrical character of polymers is insulating because of their very low concentration of free charge carriers, polymer nanocomposites (also called nanodielectrics) appear to be dielectrics or in other words, materials that will be polarized by applying an external electric field. Nano composites are closely associated with the development of cutting-edge electronic and optoelectronic devices. The nanoscale has been reached on the dimensional scale of electronic devices. The usefulness of polymer/inorganic molecule nanocomposites varies greatly, with various potential applications as well as different types of nanocomposites.