Abstract: Liquid carboxyl-terminated polychloroprene(CTCP) was synthesized by means of emu-lsion polymerization using cyclohexone peroxide(CHPO)-ferrous sulfate as redox initia-tor.During polymerization process,chloroprene and CHPO solution were added to the rea-ction mixture continually. The results of IR and NMR determination of CTCP indcate that chloroprene units are mainly of trans 1,4-structure and connecte each other in the head-to-tail form. Epoxy resin could be toughened by this liquid rubber in certain extent.