Impregnation was used to affix bis(2-ethylhexyl) phosphate (HDEHP) to the dodecylamino group of a polymer chain grafted onto a 6-nylon fiber. The distribution coefficients of Nd and Dy ions on the fiber agreed well those for HDEHP in dodecane. HDEHP supported on the hydrophobic graft chain was found to behave similarly to HDEHP dissolved in organic solvent. Nd and Dy ions were successfully separated by elution chromatography with an HDEHP-impregnated fiber-packed bed, and leakage of HDEHP from the bed was found to be negligible during the chromatography.