Benzenesulfonate (Bs) groups were introduced to the terminal of poly(ethylene oxide) (PEG) and poly(propylene oxide) (PPO) oligomers with molecular weight (MW) of 300-6000 to design an ion conductive amorphous matrix. The phase of these PEG-salt hybrids was mainly influenced by the MW of the polyethers. PEO oligomers having benzenesulfonate group(s) with MW less than 600 showed amorphous phase in the bulk in a wide temperature range (-120 similar to +150 degrees C). The ionic conductivity of these amorphous salts was considerably influenced by the glass transition temperature (T-g). The T-g of these PEG-salt hybrids was influenced by the fraction of salt group in the matrix. Among totally amorphous salts, the best ionic conductivity of 2.95 x 10(-5) S cm(-1), at 50 degrees C was obtained in the PEO(550)-BsCs. Though PEO(350)-BsM was also an amorphous salt, lower ionic conductivity was observed because of higher T-g than that of PEO(550)-BsM However, PEO(350)-BsM was useful as electrolyte in PEO oligomers because of excellent compatibility with the PEO oligomers. The ionic conductivity of PEO(350)-BsM in PEO(300) (MW of 300) was 40 times higher than that of PEO(350)-BsM in the bulk. Since PEG(350)-BsM was inherently ion conductive, the ionic conductivity for PEO(350)-BsM/PEO(300) was kept high regardless of the salt concentration.