The uptakes of cycloalkanes (C5 -C8) and bicyclic aromatic compounds (naphthalene, biphenyl, and azulene) by both strong acid cation (Dowex 50W-X4 and X8) and strong base anion (Dowex 1-X4 and X8) exchange resins have been studied in aqueous solutions at 25˚C; their distribution constants (K) have been determined. The relationship between the octanol-water partition coefficient and the resin affinity for solutes has been analyzed. The K values of three aromatic compounds were found to be much higher than expected from the octanol-water partition coefficients. This is probably due to the π interaction of aromatic rings with the resin matrix. Microscopic observations revealed that azulene molecules are uniformly distributed inside a resin particle.