The immobilization of a strong metal chelator di(2-ethylhexyl) dithiophosphoric acid (DEHTPA) on poly(4-vinylpyridine) macroporous resin (Reillex(tm)HP and Reillex(tm)425) has been investigated. DEHTPA (ligand) adsorption mechanism was proposed on the basis of the SIR morphology and IR spectrophotometry study. Analysis of the ligand distribution between the poly(4-vinylpyridine) support and the aqueous phase was performed using curve-fitting computerized method. Equilibrium constants characterizing the DEHTPA - pyridine group interaction have been evaluated. Pore volume increase, due to this interaction, are noted. Preliminary metal extraction studies were performed.