The present invention may provide a process for producing a water-absorbent resin by employing a reversed suspension polymerization method, by which a water-absorbent resin having a small particle size and a narrow particle size distribution can be produced. The process for producing a water-absorbent resin may include subjecting a water-soluble ethylenically unsaturated monomer to a reversed phase suspension polymerization in a petroleum hydrocarbon dispersion medium containing a surfactant and a polymeric dispersion agent, wherein the polymeric dispersion agent is a polymeric protective colloid having a weight average molecular weight (Mw) of 2,000 to 15,000 and a molecular weight distribution (Mw/number average molecular weight (Mn)) of 3 to 50.