6-Deoxy-6-mercaptocellulose and its S-substituted derivatives were synthesized from 6-bromo-6-deoxycellulose and their sorption behavior for metal ions was examined. Carboxyl, amino, isothiouronium, mercapto and additional hydroxyl groups were introduced to cellulose. The first two groups were effective for the sorption of many kinds of metal ions. Ag(I) was sorbed strongly by all the derivatives studied. Many derivatives sorbed large amounts of Hg(II). Competitive sorption experiments showed that Ag(I) was sorbed preferentially by most of the cellulose derivatives and that a cellulose derivative having an isothiouronium moiety sorbed Hg(II) in a comparable amount to Ag(I).