[en] The products of gallium molybdotungsten heteropoly complexes (MTHC) with variable content of Mo and W in a ligand have been studied by the method of electron paramagnetic resonance (EPR). The objects of investigation are molybdotungsten heteropoly blues (MTHB) of gallium prepared by chemical, electrochemical reduction of MTHC and by simulation from the initial components. On the base of EPR data and electron spectra change of electron localization degree on a donor atom with the increase of donor atoms in heteropolyanion is shown