ABSTRACT. – Water pollution caused by toxic cyanobacteria is a worldwide problem that increases with eutrophication. A shrimp shell adsorbent modified by alcohol/ZnSO4 was employed herein to remove Microcystis aeruginosa. The modification effects of the volume ratios of the alcohol/ZnSO4 solutions, modification reaction temperature, and modification reaction time on the shrimp shells were studied using single factor experiments. The optimum modification parameters were also obtained. Under optimal conditions, the removal efficiency of the alcohol/ZnSO4-modified shrimp shell adsorbent on the M. aeruginosa cells was 78.38 % when the added concentration of the modified shrimp shell adsorbent was 14 g/L. The present study provides a promising technique of removing toxic cyanobacterial blooms.