The structure, thermal expansion coefficients, and electric conductivity of Ce1-xGdxO2-x/2 (x = 0 ~ 0.6) solid solutions, prepared by gel-combustion method, were investigated. The uniform small particle size of the gel-combustion prepared materials allows sintering of the samples into highly dense ceramic pellets at 1300°C, a significantly lower temperature, compared to that of 1600~1650°C required for ceria solid electrolytes prepared by traditional solid state techniques. XRD showed that single-phase solid solutions have been formed in all investigated range. The maximum conductivity, σ600°C = 5.26×10-3S/cm, was found at x = 0.2. The thermal expansion coefficient, determined from high-temperature X-ray data is 8.125×10-6 K-1 at x = 0.2.