3-Chloro-2-(chloromethyl)-1-propene(CCMP) was synthesized and used to initiate atom transfer radical polymerization(ATRP) of styrene catalyzed by copper(Ⅰ) chloride/2,2′-bipyridine at 125℃.As a difunctional initiator,CCMP can initiate ATRP of styrene with two living end sites at the same time.The structure of the obtained α,ω-chloropolystyrene was confirmed by()1H-NMR spectra.The living character of the ATRP process is indicated by narrow molecular weight distributions of the obtained polystyrene(Mw/Mn<1.5),a linear(ln([M]0/[M])) versus time profile and predictable molecular weights proportional to monomer conversion.