The plasma-initiated emulsion polymerization of MMA in the presence of 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) was first investigated. The polymers were characterized by GPC, H-1 NMR, DSC and SEM. The results exhibit controlled polymerization characters: well-controlled molecular weight, relatively narrow polydispersity, molecular weight linearly increasing with conversion and successful chain extension reactions. The influence of the amount of the sodium dodecyl sulfate (SDS), CPDN concentration, plasma duration time on the polymerization rate, and micro-shape of the particle was investigated in this work. The plasma-initiation emulsion polymerization of octyl acrylate (OA) in the presence of CPDN is also carried out.