Phase composition, electric conductivity, stability of characteristics of a number ofspecimens of systems ZrO2-Sc2O3 (4.5–6.0 mol. %) and with addition 1 mol.% CeO2, prepared by usual ceramic method at the sintering temperature of 1800°С (in a vacuum) with subsequent annealing at the temperature of 1150°С (in air) were investigated by methods of X-ray investigation, temperature dependence of electric conductivity (350–750°C), cyclic resort tests at the temperature of 700°C.