Abstract: The complexation between crown ethers and rare earth ions was detected by paper-chromatographic method and stastic adsorption equilibrium. The effect of counter-anion has also been studied.The crbwn ethers used were: Benzo-15-C-5, Dibenzo-18-C-6, Cylic tetra-mer of tetrahydrofuran and acetone, Benzo-15-C-5-formaldehyde copolymer and Dibenzo-18-C-6-formaldehyde copolymer.The main experimental results obtained are as follows:1. The order of stabity of complexes of various crown ethers with rare earths is: Benzo-15-C-5>Dibenzo-18-C-6>>Cyclic tetramer of tetrahydrofuran and acetone, and Benzo-15-C-5-formaldehyde copolymer>Dibenzo-18-C-6-formaldehyde copolymer.2. The order of stability of complexes of rare earth ions is- Sm³⁺ > Er³⁺=La³⁺ (by paper chromatographic test), and Er³⁺>Eu³⁺>La³⁺ (by method of adsorption equilibrium).3. The order of stability of ion-pairing with counter anions is: picrate> trichloroacetate>sulphonsalysilate>>Cr, NO₃^-, ClO₄^- and SO₄⁼.