The kinetics of copolymerization of acrylonitrile with methyl acrylate initiated by aqueous sulite-chlorate redox system were studied in the presence of polyvinylpyrrolidone (PVP) as an emulsifier. The PVP was found to affect the polymerization rate, conversion, and relative molecular mass of polyacrylonitrile copolymer. The PVP in the polymerization solution was found to increase the polymerization rate particularly by reducing radical induction periods and the polymerization activation energy. A suitable kinetic scheme has been proposed and discussed to account for the experimental data.