In order to examine the mobility of lattice oxygen in magnesium vanadates, these catalysts were employed for the oxidative dehydrogenation of propane in the absence of oxygen for 2.25 h, followed by the addition of gaseous oxygen into the feedstream. Depending on the degree of the abstraction of lattice oxygen from these catalysts during the oxidation in the absence of the gaseous oxidant, oxygen in the effluent was detected at approximately 1.4 and 9 min with Mg3V2O8 and Mg2V2O7 respectively, after the addition of gaseous oxygen under the present reaction conditions. However, no oxygen was detected with MgV2O6 even after 18.5 min from the addition of gaseous oxygen. V-51 MAS NMR was also employed for the observation of redox behaviors of vanadium species in these catalysts during the reaction.