Crosslinked polymers having a pyrrolidinone moiety (CPS, CPES, and CVP) were synthesized by radical copolymerization of 4-(2-oxo-1-pyrrolidinyl) methylstyrene, 4-[2-(2-oxo-1-pyrrolidinyl)ethoxy]methylstyrene, or 2-vinylpyrrolidinone with divinylbenzene in the presence of AIBN as a radical initiator. The adsorption-desorption behavior of phenols on these polymers was investigated. The polymers with spacers between the polymer main chain and pyrrolidinone moiety appeared to have a superior adsorption capability to those without such spacers. The amount of phenol adsorbed on the polymers in a solvent decreased in the following order : water > chloroform > methanol. In methanol, the interaction between the polymers and phenol was suggested to come only from charge-transfer stacking (C-T stacking), whereas in chloroform the interaction was caused mainly by both hydrogen bonding and C-T stacking. The interaction in water was attributed not only to both hydrogen bonding and C-T stacking, but also to a hydrophobic interaction. Characterization of polymers (CVP) containing adsorbed phenol was carried out by thermogravimetric analysis (TGA). The TGA curves indicated a two step weight-decrease, namely the first step in the temperature ranging from ca. 100-200-degrees-C was attributed to the desorption of phenol while the second step in the temperature ranging from ca. 350-500-degrees-C was based on thermal decomposition of the polymers. The desorption of phenol adsorbed on the polymers in water indicated an inverse tendency to the adsorption; that is, the amount of phenol desorbed from the polymers without a spacer was more than those from the polymers with spacers.