Solid polymer electrolytes (SPEs) have been attracted as promising safe electrolytes, requiring high mechanical properties without sacrificing ion conductivity. Here, we prepare the SPEs with a commercially available epoxy resin, silica nanoparticles and a solvating electrolyte containing Li salt and glyme, by simple thermal curing process. The epoxy resin can provide good processability, dimensional stability and mechanical strength, and a solvating electrolyte maximizes ionic conductivity. We investigate the effect of silica nanoparticle content on ionic conductivity and glass transition temperature, using dielectric spectroscopy and DSC.