Methylcellulose-Sodium Iodide (MC-NaI) solid polymer electrolyte was prepared using solution cast technique and the conductivity and permittivity characteristics of the material were studied. FTIR studies confirmed that NaI plays a role as the conducting ions without altering the molecular structure of the polymer. Using Electrical Impedance Spectroscopy technique, it was found that the conductivity of MC-NaI polymer matrix to be the highest at 40 wt% NaI (2.70x10-5 S/cm). Conductivity of MC-NaI also increases with temperature, but decreases as temperature exceeds 333K. Dielectric studies of the material also confirm these findings, where it was found that dielectric constant and dielectric loss to be the highestat 40 wt% NaI at low frequency.