Enzyme-catalyzed polymerization in vitro has gained considerable attention in the last two decades as an efficient tool in the preparation of various polymers, such as such as polysaccharides, polyesters, polyphenols and polyaromatic anilines. The enzymatic polymerizations of vinyl monomers, however, are much less investigated these years. One important reason could result from that the majority of common vinyl monomers are barely soluble in water, which was traditionally perceived as the suitable medium for enzyme reactions. Enzymatic miniemulsion polymerization is proposed in the work as a novel way to polymerize hydrophobic vinyl monomers such as styrene. By applying enzyme-catalyzed polymerization in the miniemulsion, stable poly(styrene) latex was synthesized with a particle size range 60 to 200nm. A very low amount of enzyme and surfactant are required to facilitate the miniemulsion polymerization while a high polymerization rate and conversion could be achieved.