The oxygen fluxes of acceptor-doped LaAlO3 (La0.9Sr0.1Al0.9Mg0.1O3-delta, LSAN19191) and ceria (Ce0.8Gd0.2O2-delta, GDC20) were measured and compared as a function of temperature (1300-1600 degreesC) and oxygen partial pressure (P-O2=0.21-10(-9) atm). The oxygen permeation driven by P-O2 gradient was measured by either gas chromatograph or oxygen sensor. The measured oxygen fluxes were compared with those estimated from the measured (GDC20) or the reported (LSAM9191) electrical conductivity [Solid State Ionics 154 (2002) 535]. The oxygen flux of GDC20 was about one order of magnitude higher than that of LSAM9191 in most P-O2 gradient. (C) 2004 Elsevier B.V. All rights reserved.