A composite of carboxymethyl cellulose (CMC) and cerium oxide (CeO₂) nanoparticles was synthesized using the solution cast method with CeO₂ concentrations of 5 %, 10 %, and 15 %. Surface topography, dispersion, and elemental composition were analyzed via SEM and EDX, while impedance spectroscopy was performed at temperatures of 298-373 K over a frequency range of 50 Hz-1.2 MHz. The study revealed that temperature and CeO₂ concentration significantly influence the composite properties. D.C. conductance increased with temperature and CeO₂ content, rising from 2.8 × 10