Starch/bentonite grafted itaconic acid (IA)-acrylamide (AM) superabsorbent (SBPIAAM) is prepared by solution polymerization method with potassium persulfate as initiator. The influence of the ratio of itaconic acid and acrylamide, the neutralization degree of itaconic acid, the crosslinker and initiator dosage on the swelling performance of SBPIAAM is investigated. The optimum reaction condition is shown as follows: 9.1: 0.9 of the ratio of acrylamide and itaconic acid by mass, 70% of the neutralization degree of itaconic acid, 0.05% of crossli...