In this study, we combined the kinetic measurement and the computational simulation to build a kinetic model for the hybridization of cobalt-mediated radical polymerization (CMRP) and atom transfer radical polymerization (ATRP), which is a novel method for the one-pot synthesis of block copolymers of less activated monomers and more activated monomers, such as PVAc-b-PMMA and PVAc-b-PSty. The rate constants of the two most important reactions for PVAc radical, the dissociation of PVAc-Co-III(acac)(2) and the deactivation with Cu-III(PMDETA)Br-2, have been evaluated at 40 degrees C as 4.99 X 10(-3) s(-1) and 4.19 X 10(6) M-1 s(-1), respectively. These two kinetic parameters associated with other rate constants allowed us to build a quantitative model that can simulate the polymerization behavior observed in the hybridization of CMRP and ATRP and thus rationalize the mechanism more precisely.