Activity of La0.8Sr0.2FeO3 (LSF) to the fuel electrode reaction in Solid Oxide Reversible Cells (SORCs) was investigated by using La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) and Ba0.6La0.4CoO3 (BLC) as electrolyte and air electrode, respectively. In electrolysis mode (SOEC), LSF electrode exhibited small overpotential under the atmosphere without H2 co-feeding; the current densities reached -1.42, -0.92, -0.36 A/cm2 at 1.4 V at 900, 800, 700 °C, respectively and H2 formation rate is well agreed with that estimated by Faraday's law. On the other hand, in the SOEC-SOFC reversible mode with the gas composition of 20% steam /20%H2/60%Ar, the maximum power densities of 0.42, 0.28, 0.11 W/cm2 were achieved at 900, 800 and 700°C, respectively. In addition, the cyclic reversible operation was also investigated at 800°C, and it was found that the cell showed high stability over 30 cycles. DC polarization measurement suggests that the exchange current density of LSF is 14 mA/cm2 at 700°C, which is almost the same with that of Ni-YSZ reported. XRD measurement and SEM observation after the reversible measurement suggest that LSF is highly stable under SOEC-SOFC cyclic operation condition. Therefore, LSF is promising as the fuel electrode for SORCs, although the conductivity is not sufficiently high as electrode.