The aim of this study is to prepare alginate‐based nanocomposite for protein adsorption. Nanocomposite is prepared by dissolving alginate in the nanocellulose (NC) suspension and injected in calcium chloride bath to form alginate/NC beads. Herein, nanocellulose contents are used as a variable to study protein adsorption behavior. Protein adsorption is studied by batch method. Parameters of adsorption including effect of pH and isotherm adsorption are investigated. The results show that the optimum pH value for protein adsorption is 4 for all compositions of nanocomposites. Based on the equilibrium data for adsorption isotherm, it is shown that Langmuir isotherm model is better than Freundlich model for all compositions of alginate/NC composites. Increasing maximum adsorption capacity of alginate/NC nanocomposite was influenced slightly by nanocellulose content.