This study ascertained that Lactabacillus reuteri 6126 could produce bacteriocin.The fermentation supernatant of the strain exhibited a broad spectrum of antagonistic activity against various species gram-positive and gram-negative bacterium. The fermentation supernatant of the strain was heat-stable (30rain at 100℃) and remained active after incubation from pH 2.0 to 10.0. The fermentation supernatant of the strain was found to be sensitive to proteolytic enzymes(pepsin, trypsin, papain, proteinase K).