The present invention provides a water-absorbent resin produced by a reversed-phase suspension polymerization method, which contains a small amount of a petroleum hydrocarbon dispersion medium remaining therein used in reversed-phase suspension polymerization, and thus reducing an odor originating from the petroleum hydrocarbon dispersion medium, when the water-absorbent resin absorbs water, and also which is suitable for use in hygienic materials; an absorbent material and an absorbent article. More particularly, the present invention provides a water-absorbent resin obtained by subjecting an aqueous solution of a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a petroleum hydrocarbon dispersion medium in the presence of a surfactant, wherein the amount of the petroleum hydrocarbon dispersion medium remaining in the water-absorbent resin is 2,000 ppm or less; and an absorbent material and an absorbent article using the same.