The influences of the incorporation of copper(II) cations into MgV2O6, Mg2V2O7 and Mg3V2O8 on the catalytic activities and the mobility of lattice oxygen in those catalysts have been investigated to observe the contribution of lattice oxygen in magnesium vanadates to the oxidative dehydrogenation of propane. The incorporation of Cu2+ into those magnesium vanadates resulted in the decrease of the selectivity to propylene, while the evident enhancement of the reaction rate per unit of the surface area was observed. In order to examine the mobility of lattice oxygen in those Cu2+ incorporated catalysts, those magnesium vanadates incorporated with Cu2+ at the atomic ratios of Cu/[Mg + Cu] = 0 and 0.10 were employed for the oxidative dehydrogenation in the absence of oxygen for 2.25 h, followed by the addition of gaseous oxygen into the feed-stream. After the addition of gaseous oxygen under the present conditions, oxygen in the effluent gas was detected at approximately 36, 7 and 2 min with MgV2O6. Mg2V2O7 and Mg3V2O8 while no oxygen was detected from those catalysts incorporated with Cu2+ even 60 min after the addition of gaseous oxygen. Therefore, the incorporation of Cu2+ into those magnesium vanadates results in the enhancement of the abstraction of lattice oxygen from the catalysts. V-51 MAS NMR and XPS revealed that redox of vanadium and copper species in those catalysts contributed to the abstraction of the lattice oxygen from the corresponding catalysts. (C) 2004 Elsevier B.V. All rights reserved.