Semiconducting oxides such as Bi4Sr3Ca3CuyOx(y=0–5) and Bi4Sr3Ca3−zLizCu4Ox(z=0.1, 0.5, and 1.0), many of which become superconductors in their glass‐ceramic phases, have been studied over the wide temperature (77–450 K) and frequency (100–104Hz) ranges. The universal power‐law behavior [exponents≤1 in &sgr;(&ohgr;)=&sgr;0+A&ohgr;s] is found to be valid for most of these glasses. Little deviation from this limiting behavior is also observed for some glass compositions in the low‐temperature and high‐frequency regions. The correlated barrier hopping model based on the pair approximation is found to be more appropriate for explaining the frequency and temperature‐dependent ac conductivity data. The random walk type of model, on the other hand, is found to be valid for a limited range of temperature.