The effect of vanadium loading on the physico-chemical properties and catalytic performances of vanadium impregnated on Al0.5Ga0.5PO4 has been studied. The pure support and V-based samples have been tested in propane ammoxidation and characterized by N-2-physisorption, TEM, NH3-chemisorption, Xray diffraction, RAMAN spectroscopy, XPS and TPR-H-2. Crystalline V2O5 has been detected in all V-based catalysts. Vanadium oxide promotes the crystallization of the Al0.5Ga0.5PO4 support. The catalyst containing 5 wt.% of vanadium presents the highest selectivity toward acrylonitrile. This better catalytic performance in propane ammoxidation appears closely related to the redox properties of V catalysts. However, the catalyst containing 2 wt.% of vanadium exhibits the highest activity expressed as moles of propane converted/moles of V x min. The activity would be related to the acidity of the V-based catalysts. (C) 2012 Elsevier B. V. All rights reserved.