Oxygen ion conducting ceramics (Sc 2 O 3 ) 0.1 (ZrO 2 ) 0.9 , (Sc 2 O 3 ) 0.1 (CeO 2 ) 0.01 (ZrO 2 ) 0.89 and Ce 0.9 Gd 0.1 O 1.95 were sintered from powders with different specific surface areas. The produced ceramics were studied by scanning electron microscopy and impedance spectroscopy methods. Impedance spectroscopy measurements were performed in a wide frequency range of 10 Hz–3 GHz at temperatures up to 900 K in air. Temperature dependences of bulk and total ionic conductivities of ceramics were investigated. High bulk ionic conductivity of the order of 1 S/m at 900 K for 10ScSZ and 10Sc1CeSZ ceramics was achieved. Total ionic conductivity for both types of 10GDC ceramics was of the order of 0.1 S/m at 700 K.