The interaction between solutes and semipermeable membranes is an important factor for the membrane-separation process. As an extension to previous works, we studied the adsorption properties of cyclic compounds on cellulose acetate, a material commonly used for semipermeable membranes, in aqueous solution systems by high-performance liquid chromatography (HPLC). Cycloalcohols, cycloethers, amino acids, heterocyclic aromatic compounds, and nucleosides were used in this study. The logarithm of the capacity factor (log kΠ) for these compounds was linearly correlated with the logarithm of 1-octanol/water partition coefficients (log K o/w ) as well as noncyclic compounds. Cyclic compounds were relatively retained more than were noncyclic compounds in spite of their hydrophilic properties, which indicates the structural effects of the solute molecule on the adsorption. Although noncyclic compounds were retained mainly by hydrophobic interaction, the retention of cyclic compounds was suggested to be controlled by their inclusion within the micropore in cellulose acetate. The adsorption of heterocyclic aromatic compounds was not influenced only by ionic dissociation but also by tautomerism.