The block polymer poly(carprolactone)-poly(quaternary ammounium salt) (PCL-b-PJDMA) was synthesized through ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP) reaction.The synthesis procedure was composed of following 4 steps:(1) LPCL was synthesized via ROP reaction of -caprolactone using laurinol as an initiator; (2) LPCL was functionalized to get a macrointiator PCL-Br for ATRP by the reaction with 2-bromine butyryl bromine (BIBB); (3) the quaternary ammounium salt named with JDMA was synthesized by quaternarization of methyl chloroacetate and dimethylaminoethyl methacrylate; (4) LPCL-b-PJDMA with different unit ratios were synthesized through ATRP reaction of JDMA using PMDETA/Cu(Ⅰ)Br as a catalyst and different unit number PCL-Br as the macrointiator.The molecular structure was mainly confirmed by 1H-NMR.Thermal behavior and hydrophilicity of polymers were measured by differential scanning calorimetry (DSC) and water contact angle experiments of the polymer membrane

respectively.The anti-bacterial property of the polymer films was measured by testing the survival rate of bacteria living on the films.The results showed that the Tc of obtained PCL-b-PJDMA first reduced and then increased with the increase of PCL units in PCL-b-PJDMA.All LPCL-b-PJDMA displayed better hydrophilicity than pure PCL and the hydrophilicity of LPCL-b-PJDMA was related to the ratio of PCL to PJDMA.The bacterial experiment result showed that all the polymer films had anti-bacterial ability to both gram-negative bacteria and gram-positive bacteria.