The series of Gd-Bi-Ce-O solid solutions were synthesized by co-precipitation method with sonication. These mesoporous nanocrystalline powders with the size of about 15nm were used as precursors to ceramics formation, sintered at 1000°C in air, for the application of materials as an electrolyte for IT-SOFC. The electrical conductivity of these materials was measured by AC impedance spectroscopy in the temperature range of 450–750°C in air. It was showed that Gd0.05Bi0.15Ce0.8O2 ceramics, prepared through acetylacetonate complex, is the perspective system for this goal and has the conductivity of 5·10−3S/cm at 600°C in air.