Previously, it was found that the luminescence spectrum excited by the electrolyte ions, are sensitive to the nature of the sample and the electrolyte, which is in contact with the sample [1, 2]. Because of large specific surface area of yttrium oxide powders the luminous intensity is high. To clarify the luminescence mechanism it is important to investigate the spectral characteristics of 32 OY powders.   32 OY powders activated with Eu and Er were chosen for measurements. Aqueous solutions of pH from 3 to 9 were used as electrolytes. Luminescence spectra were recorded at room temperature in the spectral range from 500 nm to 700 nm. Bands with maxima located near 590, 615 and 645 nm were observed in the Eu OY  32 luminescence spectrum excited by electrolyte ions.     It was shown pH-change of the electrolyte did not stimulate additional bands and caused light intensity redistribution between the bands. Some activator ions influence on Eu luminescence intensity in yttrium oxide was examined. Emission intensity is significantly reduced by addition of Er to the powders, which can be explained by concentration quenching of Eu by the erbium. It is found that the luminescence spectrum excited by the electrolyte ions, are sensitive to the composition of 32O Y powders. Predictions of the emission mechanism and physical and chemical properties of the luminophore surface can be made by the mentioned spectra.     Isostructural replacement at almost constant volume activator occurs when 32 OY is activated with rare earth elements atoms. We observed bands which were related to 3Eu ions. The occurrence of these bands can not be explained by luminescence centers ionization by electrolyte ions. It was previously assumed that located near the surface activator can not be excited itself, but should have its own defects to stimulate luminescence. Evidently that the proton, generated by water dissociation, promotes ionization that structurally related to lattice defect luminescence centers. The energy released during lattice defects and released electrons recombination is transferred from the defect to the luminescence center, which leads to it excitation.     Thus, these results indicate that the observed yttrium oxide powders luminescence in contact with the electrolyte can not be explained only by radiation centers ionization, as it was suggested previously, but associated processes that occur on the surface of the luminophore.