Graft polymerization of styrene onto cellulose was investigated using eerie ions redox systems as initiator. The effects of reactant concentrations and of processing variables on the molar mass of grafted styrene on the cellulose were studied. A statistical model with the D-optimal design was used to describe the system. The optimum polystyrene molar mass obtained by simulation was compared to experimental data. The optimal reaction conditions for such a reaction were determined.