Vanadium and/or magnesium substituted aluminophosphate with ALPO(4)-5 structure have been prepared by hydrothermal synthesis. These catalysts have been tested for the oxidative dehydrogenation (ODH) of ethane. ALPO(4)-5 has a low activity and low selectivity for the ODH of ethane. The presence of Mg2+ ions in MgAPO-5 increases the selectivity to ethene, while the presence of V5+ species in VAPO-5 increases both the activity and the selectivity for this reaction. The presence of Mg2+ and V5+ species in the vanadium-magnesium alumino-phosphate (MgVAPO-5) results in a more selective catalysts for the ODH of ethane. The behavior of MgVAPO-5 could be attributed to the presence of acid sites (Mg2+) near to the redox sites (V5+) in the molecular sieve framework.