Partial electronic and oxide ion conductivity in La0.7Sr0.3Ga0.6Fe0.4O3 (LSGF) was investigated in this study by the ion blocking method. It was seen that LSGF stably exhibits the electronic hole conduction over wide oxygen partial pressure. The estimated oxide ion conductivity decreased with decreasing P-O2 and this seem to be caused by decreasing amount of V-(O) over dot which is balanced with Fe valence number. The estimated transport number of oxide ion is reasonably agreed with those estimated by oxygen concentration cell. It was found that the theoretical oxygen permeation rate in LSGF is much larger than that of observed value. Therefore, it is expected that the oxygen permeation rate could be improved by increasing activity of surface catalyst. (C) 2004 Elsevier B.V. All tights reserved.