The living/controlled radical polymerization of styrene was investigated with a new initiating system, DCDPS/FeCl3/PPh3, in which diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS) was a hexa-substituted ethane thermal iniferter. The polymerization mechanism belonged to a reverse atom transfer radical polymerization (ATRP) process. The polymerization was controlled closely in bulk (at 100 degrees C) or in solution (at 110 degrees C) with a high molecular weight and quite narrow polydispersity (M-w/M-n = 1.18 similar to 1.28). End-group analysis results by H-1 NMR spectroscopy showed that the polymer was omega-functionalized by a chlorine atom, which also was confirmed by the result of a chain-extension reaction in the presence of a FeCl2/PPh3 or CuCl/bipy (2,2'-bipyridine) catalyst via a conventional ATRP process.