N-(p-Tolyl)-N’,N’-diethyldithiocarbamoylacetamide was prepared and used as a new photoiniferter for polymerization of styrene in bulk under UV light. This photopolymerization showed some specific character, i.e., molecular weights of resulting polymers increase with reaction time and monomer conversion, respectively. The reversible reaction between growing radical and dormant species was confirmed by electron spin resonance using 2-methyl-2-nitrosopropane as a spin trapping agent. Thus, the end functionalized polymer, N,N-diethyldithiocarbamoyl-terminated polystyrene, reinitiated photopolymerization of methyl methacrylate and vinyl acetate to form block copolymers. The molecular weight distribution about 2.7 indicated that the polymerization is not a strictly living radical polymerization.