Sr₃Fe₂O_7-δ with layered perovskite structure shows an excellent oxygen storage performance and has significant potential in the fields of oxygen separators/sensors and the purification of polluted materials such as automobile exhaust gas. This review introduces effects of Pd loading on Sr₃Fe₂O_7-δ and of doping with other transition metals (Mn, Co, Ni) into the Fe sites of Sr₃Fe₂O_7-δ. Pd loading dramatically improves oxygen release rate under H2 atmosphere, because Pd species enhances the adsorption and dissociation of H2. Mn doping of Sr₃Fe₂O_7-δ also increases the oxygen release rate of Sr₃Fe₂O_7-δ. Although the local structures around the transition-metal species in Sr₃(Fe_0.8Co_0.2)₂O_7-δ and Sr₃(Fe_0.8Ni_0.2)₂O_7-δ are largely disordered by the release of lattice oxygen, the cation ordering of the as-synthesized Sr₃(Fe_0.8Mn_0.2)₂O_7-δ was maintained by doping with Mn, even in the reduced state. These results indicate that the oxygen release rate under H₂ atmosphere largely contributes to the surface reaction and structural changes in the perovskite structures upon release of lattice oxygen.