Fine fibers (80 mesh over and 300 mesh-screening residue, S4) were isolated from highly beaten pulp (NBKP, 92° SR) and their adsorbing characteristics were compared with those of beaten and unscreened sample (S2) and long fibers (80 mesh-screening residue, S3). The metallic ion-adsorbing characteristics of fine fibers were clearly distinguished among those of samples. Namely, the beating degree became lower by the addition of ferric ion to each sample, and above all, the rate of decrease of the beating degree was remarkable for S2 and S4. When ferric ion was compared with aluminium ion, it was observed that the rate of decrease of the beating degree was larger for ferric ion, and aluminium ion affected the decrease of the beating degree in the lower concentration range than ferric ion. When ferric ion was used as a metallic ion, the amount of adsorbed ferric ion was influenced by the liquor ratio, concentration and time. Especially, it was found that the largest difference of the amount of adsorption among samples was attained by selecting the liquor ratio properly. Among the samples, S2 showed the largest amount of adsorption. It was also observed that the activity of S4 in the adsorbing reaction was extremely high as compared to that of S3. As for the interactions of fine fibers with fillers and size, S4 was also observed to have remarkable characteristics for fixing. The contents of a few functional groups of the samples were determined, neither of which was found to be related with their adsorbing characteristics closely.