The development of solid electrolyte in place of liquid electrolyte has been recently carried out actively compare with general use past days. In this study conductivities of polyethylene oxides(PEO), which [EO]/[LiClO₄], 2:1, 4:1, 6:1 and 8:1, were measured and also different solvents, respectively. The PEO electrolyte complexed with LiClO₄, when [EO]/[LiClO₄] ratio is 8, showed good conductivity(>10^-5-S/cm) at 25℃ in dry box. And dimethylcarbonate(DMC) compared with different solvents, it showed also high conductivity.