Cellulose is an important biomass in natural material fields. Reactive polyhedral oligomeric silsesquioxane (R-POSS) bearing multi-N-methylol groups is novel high reactive POSS monomer. The nano-cellulose hybrids containing R-POSS were synthesized by crosslinking reaction. It was interesting to investigate properties and applications of hybrids containing R-POSS. In this work, nano-cellulose hybrids as novel biosorbent were used for adsorpting copper and nickel ions in aqueous solution. Adsorption kinetics and equilibrium isotherm of Cu2+ and Ni2+ on the nano-cellulose hybrids were investigated. The results showed that R-POSS had been grafted to cellulose macromolecule. The nano-cellulose hybrids could form new adsorptive position for heavy metal ions. The adsorption capacities of hybrid materials were obviously higher than that of control cellulose. The adsorption of heavy metal ions on nano-cellulose hybrids followed the second-order model. The equilibrium isotherms for adsorpting copper and nickel ions on the hybrids followed Langmuir isotherm model. Nano-cellulose materials containing POSS as biosorbents or ultrafiltration membranes would be used in separation of toxic heavy metal ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.