In this study, we attempt to synthesize novel acrylated agarose (ACAG)-based hydrogels with three different crosslinking densities. Acrylate groups were inserted onto agarose (AG) backbone through homogeneous reaction of acrylic monomers with AG backbone. Hydrogels were synthesized through radical copolymerization of a mixture of acrylic acid and 2-hydroxyethyl acrylate with ACAG in aqueous solution using ammonium persulfate as an initiator. Infrared spectroscopy (FTIR) was carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was assessed by scanning electron microscopy. The equilibrium swelling capacities of synthesized hydrogels were evaluated in various conditions. The absorbency under load and dynamic swelling kinetics of the hydrogels were also studied. Finally, the hydrogels were loaded with potassium nitrate and their potential for controlled release of this salt was investigated by conductimetry. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.