Complexes films composed of mixture of hydroxypropyl cellulose (HPC) and different concentrations of SmCl 3 were prepared by solvent casting technique. Different techniques were used to study the structural changes. The amorphousity of HPC increased with increasing Sm 3? concentration as indicated by XRD and FT-IR results. Optical absorption and fluorescence spectral analysis confirmed the presence of Sm 3? ions. Fluorescence spectra showed that the reddish-orange emission transition 4 G 5/2 ? 6 H 7/2 is more prominent. The nonlinear variation of the optical parameters with respect to Sm 3? content has been explained. The dielectric properties and ac-conductivity of these films were studied in the frequency range of 20 Hz-3 MHz at room temperature. The decrease in the dielectric constant e 0 was observed with the increase in frequency is due to dielectric dispersion. Both e 0 and dielectric loss e 00 are observed increases as Sm 3? ions concentration increased. The frequency and concentration dependence conductivity were also studied. The results showed that the conductivity increase with increasing both frequency and Sm 3? content. Real part electric modulus M 0 was lower at lower frequency but increases as frequency increased. Enhancement of both optical and electrical properties is observed which candidates the prepared films for many applications.