A series of calcium zirconate-based solid electrolytes doped with combinations of Y2O3, MgO and Al2O3 has been synthesized. The ionic conduction of these materials has been investigated by means of a conductivity experiment at a frequency of 10 kHz at different temperatures. The experimental results show that the ionic conductivity of these materials is 10-3 to 10-2 ΩMIN1 cm-1 at 1600°C. The n-type conduction for these materials was investigated by means of extraction oxygen technique. These materials possess extremely high chemical stability, high density, good strength and good tolerance against thermal shock. The experimental results show that these materials may be used as a solid electrolyte oxygen probe for rare earth or calcium deoxidized steel melts or rare earth cast iron melts.