Abstract: Some characteristic behaviours of phenol formaldehyde resins containing crown ether groups, PDB-18c6,PDB-24c8 and PB-15c5 towards U (Ⅵ)in inorganic acid medium such as HCl, H₂SO₄ and H₃PO₄ have been studied. It was shown that in hydrochloric acid medium the adsorption of U (Ⅵ) differs from that of U(Ⅵ). The difference may be used for separating uranium ions of different valency. Fe³⁺ ion was found to have inference on the adsorption of U (Ⅵ). The elution efficiency of U (Ⅵ) from the asso-ciated crown polymers by HCl decreases with increase of HCl concentration.γ-ray radia-tion with dosage up to 5×10⁸ rad shown no effect on the stability of the crown-poly-mers studied.