Methylated beta-cyclodextrin (me-beta-CD) was used to complex the hydrophobic monomers isobornyl acrylate (1) and butyl acrylate (2) yielding the water-soluble host/guest complexes isobornyl acrylate/me-beta-CD (la) and butyl acrylate/me-beta-CD (2a). The included monomers were copolymerized in water by free-radical mechanism and the kinetics were studied. In order to evaluate these results, the corresponding uncomplexed monomers 1 and 2 were also copolymerized in organic solution. The reactivity ratios of la and 20 (r(1a) = 0.3, r(2a) = 1.7) differ significantly from the reactivity ratios of the corresponding uncomplexed acrylates 1 and 2 in organic solution (r(1) = 1.3, r(2) = 1.0). In addition, we found that the weight averages of the copolymers prepared by using me-beta-CD are significantly higher than those of the corresponding polymers prepared from uncomplexed monomers in organic solution.