Well-defined polydimethylsiloxane-block-polystyrene (PDMS-b-PS) diblock copolymers were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization using a functional PDMS-macro RAFT agent. The RAFT polymerization kinetics was simulated by a mathematical model for the RAFT polymerization in a batch reactor based on the method of moments. The model described molecular weight, monomer conversion, and polydispersity index as a function of polymerization time. Good agreements in the polymerization kinetics were achieved for fitting the kinetic profiles with the developed model. In addition, the model was used to predict the effects of initiator concentration, chain transfer agent concentration, and monomer concentration on the RAFT polymerization kinetics. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1047-1055, 2012