Provided is a water-absorbent resin that increases thediffusivity of a to-be-absorbed liquid and that makes itpossible to effectively decrease the amount of re-wet. Thewater-absorbent resin is obtained by polymerizing awater-soluble ethylenicallyally unsaturated monomer under thepresence of an internal-crosslinking agent. The water-absorbentresin further exhibits a degree of swelling under aload. The water-absorbent resin can be produced by performingthe following steps in a method in which a water-absorbentresin is produced by performing reverse phase suspensionpolymerization of a water-soluble ethylenicallyallyunsaturated monomer in a hydrocarbon dispersion medium underthe presence of an internal-crosslinking agent: a step inwhich polymerization is performed under the presence of an azocompound and a peroxide； and a step in which a water-containinggel obtained by said polymerization is post-crosslinked using apost-crosslinking agent.
