A novel azo-containing dithiocarbamate, I-phenylethyl N,N-(4-phenylazo) phenylphenyidithiocarbamate (PPADC), was successfully synthesized and used to mediate the polymerization of methyl acrylate (MA) and styrene (St). In the presence of PPADC, the reversible addition-fragmentation chain transfer (RAFT) polymerization was well controlled in the case of MA, however, the slightly ill-controlled in the case of St. Interestingly, the polymerization of St could be well-controlled when using PPADC as the initiator in the presence of CuBr/PMDETA via atom transfer radical polymerization (ATRP) technique. In the cases of RAFT polymerization of MA and ATRP of St, the kinetic plots were both of first-order, and the molecular weight of the polymer increased linearly with the monomer conversion while keeping the relatively narrow molecular weight distribution (M-w/M-n). The molecular weight of the polymer measured by gel permeation chromatographer (GPC) was also close to the theoretical value (M-n(th)). The obtained polymer was characterized by H-1-NMR analysis, ultraviolet absorption, FTIR spectra analysis and chain-extension experiments. Furthermore, the photoresponsive behaviors of azobenzene-terminated poly(methyl acrylate) (PMA) and polystyrene (PS) were similar to PPADC. (C) 2008 Wiley Periodicals, Inc.