Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to control the grafting of styrene from a cellulose substrate. The hydroxyl groups of the cellulose fiber were converted into thiocarbonyl-thio chain transfer agent, and were further used to mediate the RAFT polymerization of styrene. The graft copolymers were analyzed by gravimetry, attenuated total reflectance Fourier transform infrared spectroscopy, contact angle measurements, scanning electron microscopy, differential scanning calorimetry, and thermogravimetry. The results obtained from these analytical techniques confirm that grafting occurred from the surface of the cellulose fibers. The poly(styrene) chain were also cleaved from the cellulose backbone and analyzed by size exclusion chromatography and showed narrow polydispersity.