Synthesis of superabsorbent of starch-graft-poly(potassium acrylate-co-acrylamide) has been studied by inverse suspension polymerization. In this paper, the effects of reaction conditions, such as, monomeric concentration, the amount of cross-linking agent, ratio of water to oil, reaction temperature and the best condition being able to obtain the spherical resin were investigated. Experiments show that the water-absorbing resin is strong and capable of resisting pressure of retain water. It keeps the shape of particles after absorbing water. After mixing with soil, it does not become sticky, and the coos structure can better retain air. It just fit agriculture and forest. In addition, thermogravimetric analysis revealed the superior thermal stability of the grafted product, and its large size particles also reduces risk of air pollution. Synthesis of superabsorbent of starch-graft-poly (potassium acrylate-co-acrylamide) has been studied by inverse suspension polymerization. In this paper, the effects of reaction conditions, such as, monomeric concentration, the amount of cross-linking agent, ratio of water to oil, reaction temperature and the best condition being able to obtain the spherical resin were investigated. Experiments show that the water-absorbing resin is strong and capable of resisting pressure of retain water. It keeps the shape of particles after absorbing water. After just mixing with soil, it does not become sticky, and the coos structure can better retain air. It just fit agriculture and forest. In addition, thermogravimetric analysis revealed the superior thermal stability of the grafted product, and its large size particles also reduces risk of air pollution.