Copolymers of maleic anhydride and styrene were synthesized by block-radical polymerization. The structures of cross-linked copolymers were determined by IQ-spectroscopy. Based on the obtained structure, the shape of crosslinked copolymer, which was used as a sorbent and the structure of uranyl-ions which is in hydrated form in water solution forms the chelating structure due to free electron pair of nitrogen, oxygen and recoverable ions. Detection of the best conditions of sorption of uranyl-ions by cross-linked copolymer was carried out in the experiments by varying pH at different time intervals.