The partial purification and characterization of pentocin LPEM818 produced by Lactobacillus pentosus LPEM818 were studied.Pentocin LPEM818 was purified by 80 % ammonium sulfate precipitation and Sephadex G-25 column chromatography.The results showed that an 11.09 fold purification and 4.6 % yield were obtained.Pentocin LPEM818 exhibited strong heat stability(remained 84.52 % of the antibacterial activity after 15 min at 121 ℃) and pH stability(pH 2.0-8.0).The activity of pentocin LPEM818 was destroyed after treatment with proteinase K and trypsin.The mode of action of pentocin LPEM818 was bactericidal.Pentocin LPEM818 exhibited inhibitory activity against part of the Gram-positive bacteria and Gram-negative bacteria.The identified properties of pentocin LPEM818 indicate that it is a novel bacteriocin with potential application as a bio-preservative to improve the safety of food products.