Аннотация:The purpose of this work was to investigate the sorbents on the basis of polyethylenimine (PEI) intended for collecting biomass of microalgae (MA). For this purpose, a series of porous and insoluble polymeric materials were synthesized by cross-linking of PEI with epichlorohydrine. The analysis of kinetics and efficiency of immobilization assessed for the model culture Chlorella vulgaris, revealed that already within 3 h of incubation, 39–75% of MA cells attached to the surface of tested sorbents. It was shown that on the initial stage of immobilization the sorption activity of polymeric materials depended on the “PEI:crosslinker” ratio. One of the tested sorbents was additionally quartenized by alkylation with dimethyl sulphate resulting in sharp increase of its sorption activity. The estimation of the MA desorption from polymeric surface showed that most Ch. vulgaris cells were practically irreversibly immobilized on all tested sorbents based on the PEI cross-linked with epichlorohydrine.