The present invention provides a bodily fluid-absorbent structure improved so as to facilitate bodily fluids to disperse in a thickness direction of the structure. Core material of a bodily fluid-absorbent structure is formed of an aggregation of fluff wood pulp fibers. The aggregation has a basis mass in a range of 150 to 500 g/m2 and a specific volume in a range of 3 to 20 cc/g. In the aggregation, a relationship between horizontal orientation index IH and specific volume VSP of fluff wood pulp fibers is represented by a formula as follows: IH is less than or equal to −0.099VSP+2.4.