Abstract: The ac polarographic behavior of Eu⁺³ ions in three base solutions (NH₄SCN, EDTA-NaCl,DTPA-NaCl) has been compared.In DTPA-NaCl solution the polarographic reversibility of Eu(Ⅲ)is the best among them.The optimun conditions for the polarographic determination of Eu(Ⅲ)are: pH≥6.5, NaCl concentration≥0.3M, the concentration of DTPAshould be slightly higher than the total concentration of all the metal ions which can form complexes with DTPA.Under these conditions, the lower limit of detection of Eu(Ⅲ).is 2×10^-6Mby ac polarography or single sweep oscil-lographic polarography, or 2×10^-7Mby differential pulse polarography.Other rare earth ions do not interfere.Small amounts of Eu in samples of mixed rare earth oxides were determined by this method with satisfactory results.