Provided is a water-absorbent resin that increases the diffusivity of a to-be-absorbed liquid and that makes it possible to effectively decrease the amount of re-wet. The water-absorbent resin is obtained by polymerizing a water-soluble ethylenicallyally unsaturated monomer under the presence of an internal-crosslinking agent, has the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption of 20 ml/g or more, and exhibits the degree of swelling under a load at 30 minutes of 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes from the start of water absorption is designated as the degree of swelling under a load of 100%.
