The present paper examines the influence of various reaction parameters (e.g., pH, type, and concentration of peroxide, reaction time, oxygen as well as reaction medium) on the graft copolymerization of methacrylic acid, butyl methacrylate, epoxypropyl acrylate, and epoxypropyl methacrylate onto chemithermomechanical pulps, initiated by the xanthate method. The optimum concentration of H2O2 changes with the monomer used. Among the peroxides investigated, H2O2 offered the best performance. Oxygen and organic solvents, e.g., acetone and vegetable oil, inhabited grafting reaction. In addition, epoxy monomers showed better results compared to other monomers; this may be due to the participation of epoxy groups in the polymerization reaction