Abstract: In the presence of 4-dimethylaminopyridine(DMAP), natural polymer Laminaria(Lam) was reacted with glycidyl methacrylate(GMA) via nucleophilic substitution, resulting in a novel water-soluble biodegradable crosslinker Lam-GMA. Polyacrylamide hydrogels were prepared using the Lam-GMA as crosslinker. Upon the catalysis of lipase, the swelling properties and the degradation behavior of the hydrogels were studied at physiological conditions. As a model macromolecular drug, bovine serum albumin (BSA) was embedded in the hydrogels, and the drug release behavior was studied. Results showed that the conversion of the grafting reaction was high, and the graft ratio could be controlled. More applied amount of crosslinker would lead to a longer degradation time. BSA released slowly from the degraded hydrogels upon the degradation process.