To provide a preparation process of an adsorbent that adsorbs hydrophilic materials, especially materials effecting like hormones effectively and has a high mechanical strength, an excellent adsorbing reproducibility and a reduced dissolution of disturbing materials.

A hydrophilic-material adsorbent is prepared by a process for obtaining an emulsion by dispersing an oil-soluble mixture in a dispersant aqueous solution and a following process for obtaining a crosslinked polymer by carrying out an emulsion polymerization reaction by raising the temperature of the emulsion. As the oil-soluble mixture in this process, a mixture comprising only a monomer and a polymerization initiator is used.