NO x is the main pollutant in the air, which causes many harmful effects on society. The V 2 O 5 /TiO 2 catalysts are very important to reduce the NO x from the heat engine plants and vehicle exhausts. However, various reasons will affect the performance of the catalysts. In this paper, the polymerization state of surface VO x of supported V 2 O 5 /TiO 2 catalysts was controlled by changing the pH value of the impregnation precursor solutions, and the redox and acidity properties of the catalysts can be adjusted consequently. The Raman spectroscopy, 51 V magicangle spinning nuclear magnetic resonance (MAS NMR), H 2temperature-programmed reduction (H 2-TPR), NH 3-temperature-programmed desorption (NH 3-TPD), NH 3-temperature-programmed oxidation (TPO) and 15 NH 3-NO-O 2-temperature-programmed surface reaction (TPSR) were mainly used for the characterization and properties tests of the samples. Although all catalysts in this work had similar surface morphology and the same vanadium loading, the catalyst oxidability decreased while acidity increased with the increasing of VO x polymerization, which causes the NO conversion increases with the increasing of VO x polymerization below 300°C in selective catalytic reduction (SCR) de-NO x reaction. This work will promote the advance in catalysis and anti-pollution fields for human and nature.