Novel inorganic/organic composites were constructed from highly conductive Li2S-SiS2-Li4SiO4 oxysulfide glass and Linear poly(oxyethylene)s (POEs) or high molecular weight branched POE without adding any Lithium salts. The ionic conductivity of composites was lower than that of the oxysulfide glass, but the mixing of glass powder into the POEs allowed the preparation of thin films. The composites prepared from low molecular weight linear oligomeric POEs (M-n = 600 and 1000) showed higher ionic conductivities than those from the high molecular weight POEs (M-n = 4000 and 10000). Interestingly, the composite from the high molecular weight branched POE (M-n = 1.3 X 10(5)) showed ionic conductivity comparable with those from linear oligomeric POEs and afforded a flexible film form.