Manganese-substituted AlPO4-5 molecular sieve (MnAPO-5) was characterized by temperature-programmed reduction (TPR) and diffuse reflectance UV-Vis and electron paramagnetic resonance (EPR) spectroscopies, and the results were compared with those of manganese oxides impregnated on AlPO4-5 (Mn/AlPO4-5). It, was found from TPR that the manganese interacted strongly with the aluminophosphate surface in MnAPO-5. Higher temperatures were required to reduce the manganese species on MnAPO-5 by hydrogen than to reduce those on Mn/AlPO4-5. The TPR, UV-Vis, and EPR results indicate that Mn2+ or Mn3+ was the major oxidation state of manganese in MnAPO-5, in which a small amount of MnO2 or Mn2O3 was also found. O-2(-) was observed from AlPO4-5, MnAPO-5, and Mn/AlPO4-5 by EPR at g(zz) = 2.021, g(xx) = 2.008, and g(yy) = 2.003; it existed on the surface of the aluminophosphate rather than being associated with manganese on either MnAPO-5 or Mn/AlPO4-5. A kinetic model involving oxygen and ethane adsorption was proposed for ethane oxydehydrogenation over MnAPO-5. The surface reaction was the rate-determining step. The activation energy for the reaction and the enthalpy and entropy changes for the adsorptions of ethane and oxygen were obtained in this study. Because positive entropy and enthalpy changes for oxygen chemisorption on the MnAPO-5 surface were found, it is proposed that surface rearrangement around the Mn catalytic center occurred during oxygen chemisorption.