A comprehensive kinetic model based on the mechanism of supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) was developed to better understand the kinetics of copper(0)-mediated reversible-deactivation radical polymerization [Cu(0)-mediated RDRP]. Simulation results show that diffusional limitation on termination significantly affects on polymerization. A comprehensive description of the variation trend of soluble species and reaction rates during polymerization was illustrated by simulation. The effects on kinetics of four key rate constants (i.e., k(a0), k(disp), k(a1), k(comp)) involved in Cu(0)-mediated RDRP were investigated in detail, which contributed to greater insight into the differences between the SET-LRP and SARA ATRP mechanisms. Finally, Cu(0)-mediated RDRPs of methyl methacrylate (MMA) and butyl methacrylate (BMA) were conducted to study the polymerization kinetics at 25 degrees C. Results of simulations and experiments performed under polymerization conditions show that the Cu(0) surface area-dependent apparent value follows the relationship of K-p1(4)(app)/k(p2(5))(app) alpha (S-1(4)/S-2(5))(1/2) in previously published works. Addition of an initial (CuBr2)-Br-II deactivator can significantly improve the controllability of polymerization and reduce the deviation of M from theoretical values and larger M-w/M-n at the start of polymerization.