Object:The main object of the present invention is to provide a water-absorbent resin that has an appropriate absorption capacity and excellent flow-through properties and that is suitably used in an absorbent article applied to a hygienic material, etc.Means for Achieving the Object:A water-absorbent resin formed by agglomerating primary particles according to a reversed-phase suspension polymerization method, the primary particles being obtained by polymerizing at least one water-soluble ethylenically unsaturated monomer in the presence of a dispersion stabilizer according to a reversed-phase suspension polymerization method, the primary particles having a median particle size of 100 to 250 μm, and the water-absorbent resin having a water-retention capacity of saline solution of 30 g/g or less.