To separate xylose from monosaccharide mixtures, we investigated the adsorption equilibrium of glucose, xylose, and arabinose on five different resins. The sing le-component isotherms of these three sugars were measured at 25 degrees C. All equilibrium data were described with linear isotherms. The adsorption amounts and selectivities of the above monosaccharides on these five cation exchange resins were compared. The counterions and the degree of cross-linking were the important factors influencing the adsorption behavior. The Ca(2+) loaded and 4 % cross-linked resin has the largest adsorption amounts for each monosaccharide, while the Ca(2+) loaded and 6 % cross-linked resin has the maximum selectivity factor (about 1.318) for the species of arabinose and xylose and the Ca(2+) loaded and 8 % cross-linked resin shows a better performance on the separation of xylose and glucose.