The present invention provides a particulate water absorbing agent for a thin absorbing substrate suitable for actual use. A particulate water absorbing agent having irregularly pulverized shape, characterized by comprising, a surface crosslinked water-absorbing resin obtained by crosslinking polymerization of an unsaturated monomer with an acid group and/or salts thereof, which absorbing agent contains agglomerated particles therein and further satisfies (i) centrifuge retention capacity (CRC) in a physiological saline solution of not lower than 32 g/g, (ii) mass median particle size (D50) of 200 to 400 &mgr；m, (iii) particles smaller than 150 &mgr；m of 95 to 100% by weight, and so on. By using the particulate water absorbing agent, such absorbing articles can be obtained as have few rugged surface after water absorption, excellent liquid permeation property.本發明提供一種吸水劑，如尿組成改變時亦能長期維持優異之吸水特性。此吸水劑為將不飽和單體交聯聚合所得吸水性樹脂當作主要成分之粒狀吸水劑，其對生理食鹽水之無加壓下吸收倍率(CRC)為32g/g以上、質量平均粒徑(D50)為200~400μm、粒徑未達150μm微粒佔全體之0~2質量%、可溶成分劣化增加量為0~15質量%、劣化試驗液中之1小時可溶成分為0.1~30質量%。
