A sodium starch sulfate- based superabsorbent was synthesized to improve water and saline absorbencies. A sodium starch sulfate with high degree of substitution was synthesized by the reaction of starch gelatinized with dimethyl acetamide (DMAc)/ lithium chloride (LiCl) and a dimethyl formamide-sulfur trioxide (DMF-SO,) complex. The sodium starch sulfate was then graft-polymerized with acrylonitrile and the nitrile groups of the sodium starch sulfate-g-polyacrylonitrile were converted to a mixture of hydrophilic carboxamide and carboxylate groups by alkaline hydrolysis. The hydrolyzed sodium starch sulfate-g-polyacrylonitrile copolymer exhibited improved water and saline absorbencies compared with that of existing starch-based superabsorbents, resulting from the presence of sulfate groups. The maximum water and saline absorbencies of the sodium starch sulfate-based superabsorbent were 1510 and 126.4 g/g, respectively.