Abstract: The extraction,purification and functional characterization of the bacteriocin produced by Lactobacillus plantarum M44 selected from rice noodles products of Guangxi province were studied.It was identified as Lactobacillus plantarum via using microbial morphology identification and 16 S r DNA gene sequence homology analysis.The fermentation supernatant of strain M44 have antibacterial activity,and antibacterial substances was identified as protein.The bacteriocin was purified by protein salting- out method and the optimal concentration of60% ammonium sulfate precipitation was determined.The most appropriate harvest time of the bacteriocin was 12 h by studying production of bacteriocin during the growth of strain M44.The results indicated that the lactobacillin M44 still had antibacterial activity at 121 ℃ for 15 min,and had strong antibacterial activity in the range of p H2.0~8.0,but had no antibacterial activity after pepsin and trypsin treatment,whatever lactobacillin M44 proved its good inhibitory effect on proliferation of Listeria monocytogenes,Escherichia coli,Salmonella typhimurium,and Staphylococcus aureus by the oxford cup method.In this paper a preliminary study on the bacteriocin produced by Lactobacillus plantarum M44 had been made to lay the basis for the development of natural biological preservatives.