PROBLEM TO BE SOLVED: To provide a water absorption treatment material capable of attaining a sufficient solidification strength even with a small quantity of water absorptive polymer.SOLUTION: A water absorption treatment material 1 comprises a granular core part 10 and a coated layer part 20. The coated layer part 20 covers the granular core part 10. The coated layer part 20 contains a water absorptive polymer 22 having an average particle size of 20 &mu；m or less. The weight percent of the water absorptive polymer 22 to the entirety of the water absorption treatment material 1 is 1.32% or more and 2.55% or less.SELECTED DRAWING: Figure 1
