2HHThe 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 11 of a bodily fluid absorbent structure 10 is formed of an aggregation of fluff wood pulp fibers. The aggregation has a basis mass in a range of 150 to 500g/m and a specific volume in a range of 3 to 20cc/g. In the aggregation a relationship between horizontal orientation index I and specific volume VSP of fluff wood pulp fibers is represented by a formula as follows: I is less than or equal to 0.099VSP + 2.4.
