The present invention provides a novel water-absorbent resin desirable for use as a hygienic material and the like, and an absorbent material and absorbent article using the water-absorbent resin; the water-absorbent resin having a high gel strength that prevents a reduction in liquid permeation rate by suppressing gel blocking during absorption, and an excellent water-retention capacity at the same time.The water-absorbent resin satisfies the following criteria (1) and (2):(1) having a water-retention capacity of saline solution of 40 g/g or more, and(2) having a total gel strength of 5,500 Pa or greater, the total gel strength being the sum of 30 times swollen gel strength a, 40 times swollen gel strength b, and 50 times swollen gel strength c.