Abstract Partial oxidation of propane overKeggin type molybdovanadophosphoric acids was studied. The physico-chemical properties of the catalysts were investigated by means of BET, UV-visible diffuse reflectance spectra, IR and TPR, and the preliminary structure-performance relationship was established. The substitution of Mo6＋ with V5＋ in Keggin structure decreased the vibration strength of bridging M—O bonds and significantly increased the oxidation and oxygen insertion abilities of Keggin oxoanion, thus influencing the catalytic activity and selectivity to oxygenated products. Optimized vanadium atom substitution enhanced the selectivity to acid products and the optimal selectivity could be obtained on the H5PMo10V2O40 catalyst. However, excessive vanadium substitution led to deep oxidation of the acid products. It was thought that appropriate amount of (VO)2＋and small amount of vanadic oxide species segregating from the primary and the secondary structures of the oxo-anions have an impact on the reaction performance.