The Ruddlesden-Popper (RP) compounds, Sr3Fe2O7-δ, RP n = 2, were synthesized by citrate gel method. Co was selected as dopant and substituted on Fe-site. Thermal decomposition behaviour and phase analysis of Sr3Fe2-xCoxO7-δ (x = 0 - 1.0) were characterized using Simultaneous TGA-DTA analyzer (STA) and X-ray diffractometer (XRD), respectively. The result showed a single phase obtained from the doped compositions after calcination at 1200°C. The microstructure of sintered compositions characterized using Scanning Electron Microscope (SEM) showed the porous structure as a requirement for anode material. The highest electrical conductivity in this work was obtained from Sr3FeCoO7-δ. The oxidation states of Co in Sr3Fe2-xCoxO7-δ compositions investigated by X-ray absorption near edge structure (XANES) technique were found to be +2 and +3 due to the Co K-edge energies existing between these of Co2+ and Co3+.