Abstract: Sodium polyacrylateresins were synthesized by solution polymerization method. The water absorption of resin that was influenced by various contents of potassium persulfateinitiator, N, N'-methylene bisacrylamide (MBA) cross-linking agent, starchgraft, and different degree of neutralization were intensively studied. And the optimum formula of the optimum water absorption resin was obtained. Based on theformula, water and 0.9%NaCl absorption of the composite materials with varying expanded perlite contents were fully researched.Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and X-ray diffraction (XRD) were used to measure the compose and structure characteristic of composite materials. The best solution absorption of composite materials, i.e., water absorption was 589 g/g and 0.9%NaCl absorption was 123 g/g, were found when expanded perlite content was 12%.