Method for production of absorbent resin

A method for the production of an absorbent resin having a cross-linked surface region each in the individual particles thereof, which method comprises mixing 100 parts by weight of (A) a hydrated gel of an absorbent resin which is resulted from aqueous solution polymerization having a polymerization ratio in the range of from 60 to 99%, an average particle diameter in the range of from 0.1 to 200 mm, a water content in the range of from 30 to 90% by weight, and a temperature in the range of from 40.degree. to 110.degree. C., with from 1 to 50 parts by weight of (B) a substantially dry fine absorbent resin powder having an average particle diameter smaller than the average particle diameter assumed by said hydrated gel of the absorbent resin (A) while in a dried state, then raised the polymerization ratio of said hydrated gel of absorbent resin (A) to a level higher than the polymerization ratio of said hydrated gel when being mixed thereby forming an absorbent resin to be treated, and mixing said absorbent resin to be treated with (D) a cross-linking agent and subjecting the resultant mixture to a cross-linking reaction.