To provide a process for continuously producing a resin product with high water absorbability capable of a simple and low cost continuous production of the resin product with high physical properties of water absorbability at a stable constant quality and the resin product with high physical properties and stable quality of water absorbability.

The process includes a step (A) for determining predetermined physical properties and/or a predetermined amount of component for a resin with water absorbability continuously produced by means of a classification step and/or a surface reformulation step, a step (B) for separating a resin with water absorbability exhibiting the predetermined physical properties and/or the predetermined amount of component to be a constant or over and/or a constant or below value according to the determined results from the continuously produced resin with water absorbability (a) in a predetermined amount and a step (C) for mixing at least one part of the separated predetermined amount of the resin with water absorbability (a) with a resin having water absorbability continuously produced by means of the classification step and/or the surface reformulation step in the same or an another production line.