Abstract: Five ferric compounds, α-Fe₂O₃, γ-Fe₂O₄, ZnFe₂O₄, ZnFe₂O₄ •20% α-Fe₂O₃ and ZnFe₂O₄•20%γ-Fe₂O₃,used as catalysts for oxidative dehydrogenation of butene to buta-diene were prepared and identified by X-ray diffraction. The catalytic sites on the ferrite surface were studied by chemisorption and TPD of oxygen and n-butene. It was found that ZnFe₂O₄ adsorbed more butene than α-and γ-Fe₂O₃, the later two oxides adsorbed more oxygen than the former compound,and the mixtures of the Fe₂O₃ isomers have the greater ability for chemisorption of both butene and oxygen. The reaction mechanism was discussed based on the different behaviours of these five ferric compounds acting as sorbent and oxygen-carrier in oxydative dehydrogenation of nbutene to butadiene or carbon dioxide.