This study reports the catalytic and electrochemical characteristics of La0.8Sr0.2Cr0.97V0.03O3 (LSCV). Catalytic properties of LSCV for the methane steam reforming have been carried out at 800 degreesC. This oxide exhibits a low activity. The most important fact is that no carbon deposit was detected. We have investigated electrochemical behaviour of a LSCV-YSZ composite (YSZ: yttria stabilised zirconia) in H-2-H2O and in CH4-H2O atmosphere by impedance spectroscopy. Impedance diagrams are composed of two contributions at high-frequency (HF, typically 100 Hz) and at medium-frequency (MF, typically 1 Hz). At 800 degreesC, the normalised value of the MF resistance is only three-times higher than that obtained with an optimised Ni-YSZ cermet. In fact, the large difference comes from the HF resistance which is lower for the Ni-YSZ cermet by a factor of 20. This could be explained by the microstructure of the interface of the LSCV-YSZ composite layer and the electrolyte pellet which has to be improved. In CH4-H2O, an additional semicircle at low-frequency (noted as LF, typically 0.1 Hz) is observed. This LF contribution might be associated with the catalytic rate of the steam reforming of methane reaction. Ruthenium, as a steam reforming catalyst, was added to the LSCV-YSZ electrode. At 800 degreesC, in pure methane mixed with 5% of steam, this anode material shows similar results to those observed in H-2-H2O without ruthenium. Moreover, electrochemical behaviour was stable with time and no carbon deposit was detected after 100 h of operation. These results demonstrated that the gradual methane reforming can be implemented. (C) 2000 Elsevier Science B.V. All rights reserved.