The reversible addition-fragmentation-transfer (RAFT) dispersion polymerization is a typical controlled/ling radical polymerization under heterogeneous condition

which has the advantage to prepare micro-sized or nano-sized polymer particles with well-defined polymer molecular weight and low molecular weight distribution. In this manuscript

the dispersion polymerizations mediated with a small RAFT agent and a macromolecular RAFT (Macro-RAFT) agent are reviewed

and the polymerization kinetics

the polymer particle nucleation

and the polymer particle growth during the RAFT dispersion polymerizations are introduced. The difference between the dispersion polymerizations mediated with a small RAFT agent and a Macro-RAFT agent is revealed. The small RAFT agent mediated dispersion polymerization is generally performed under the heterogeneous condition similarly with the general radical dispersion polymerization

and micro-sized polymer particles are prepared at most cases. Whereas

an initial slow homogeneous polymerization before the block copolymer micellization and a subsequent fast heterogeneous one after the block copolymer micellization are involved in the Macro-RAFT agent mediated dispersion polymerization

and nano-sized block copolymer colloids are usually prepared.