In order to clarify the mixed effect of a cation on proton conduction, the electrical conductivity and the proton concentration of SrCe0.9 (-) xZrxY0.1O3 (-) (delta) (X = 0.0, 03, 0.5, 0.7, 0.9) were measured by the AC impedance method and thermogravimetric analysis at 573-1173 K. The electrical conductivity reached a maximum value at x = 0.5. The proton concentration at x = 0.5 is the highest at this experimental temperature. The condition of the oxygen vacancy was examined by a Raman spectroscopic analysis. The Raman band around 350 cm(-1) attributed to the CeO6 stretching mode was observed and the half band width of the peak is broad when the cation on the B site is a mixture of Ce4+ and Ze(4+) It was found that the symmetry of the octahedron around B-site might be reduced due to the cation mix on the B-site. (C) 2015 Elsevier B.V. All rights reserved.