A model for the heterogeneous graft polymerization of vinyl and/or acrylic monomers on cellulose initiated by ceric ions is developed. The model can be easily extended to other (poly)hydroxylic substrates, other one-electron oxidants and homogeneous systems. Three component mechanisms are suggested to be relevant in a radical graft polymerization : from, onto and from-to. Several competitive reactions appear in the polymerization scheme that lead to related mechanistic cases. The electronic nature of the monomer and the number of polymerization sites are taken into account. Expressions for reaction parameters as a function of reaction variables are deduced. Some structural knowledge of the copolymer is derived from the model.