Inverse suspension polymerization was adopted to synthesize partially neutralized acrylic acid (sodium polyacrylate) superabsorbent resin.The effects of water phase to oil phase ratio, dispersant species, crosslinking agent and initiator dosage, reaction temperature, neutralization degree, and reaction time on the water absorption were discussed; and the water capacity was studied.The water absorption reached 606%, water capacity still kept 83% after 4h baking at 80°C when sodium polyacrylate was synthesized at the optimal formula.The hydroscopicity resin could be reused.