The synthesis of a monomer with diethyl iminodiacetate groups was investigated in order to obtain complexing copolymers. Copolymers of N-acryloyl diethyl iminodiacetate with acrylamide and acrylic acid were synthetized by a radical mechanism using 2,2＇-azobisisobutyronitrile (AIBN) as initiator in dioxane at 80-degrees-C. The compositions of the copolymers were established by H-1 nuclear magnetic resonance (NMR) spectroscopy. The reactivity ratios were determined by both Fineman-Ross and Kelen-Tudos methods. The chelating ability of the synthetized copolymers was investigated with Eu-152.