[en] An effect of polarization on structure, thermal and chemical properties of vanadium oxides and vanadates has been studied. It has been established that in the series of vanadium oxides the V⁵⁺ ions have the highest ionic potential and polarizing ability. Crystal structures of the studied vanadium oxides refer to heterodesmic structure with a mixed ionic-covalent bond. With increasing temperature the polarization effect grows thus leading to a change in electron states. The schemes are given of possible isovalent substitution of orthovanadates of Be, Ca, Sr, Ba, Cs, K, Na, Rb, Y, and lanthanides