The radical graft copolymerization of vinylpyridine derivatives onto acetyl cellulose was investigated using Fe2+/H2O2 redox system as an initiator. It was proved that the addition of hydrazine hydrate increased the degree of grafting many times. The reaction mechanism of hydrazine hydrate was also investigated. A. correlation between nitrogen content and the total anion exchange capacity was established. The vinylpyridine derivatives were ordered according to their reactivity. The effects of reaction conditions on the total anion-exchange capacity, the total conversion, the degree of grafting, and the grafting efficiency of the copolymers obtained were examined. The copolymers were characterized by IR and H-NMR spectra, thermogravimetric analysis, elemental analysis, and total anion-exchange capacity.