The purpose of this study is to investigate the partial characteristics (spectrum of antibacterial activity; sensitivity of enzymes, pH and temperature; mode of action) of the bacteriocin produced by Lactobacillus brevis KLDS1.0373 which was isolated from “Jiaoke”, a traditional, naturally fermented cream from Inner Mongolia. The bacteriocin was partially purified by ammonium sulfate precipitation followed by sequential gel filtration chromatography and the antibacterial activity of the bacteriocin was heat tolerant and was found to be stable after incubation for different pH values. The slight increase in activity was recorded after 30 min at 100 °C or 121 °C. The bacteriocin was sensitive to several proteinases, but insensitive to α-amylase. The apparent molecular weight of the partially purified bacteriocin was estimated at approximately 3.8 kD by Tricine-SDS-PAGE. The bacteriocin has a broad inhibitory spectrum against Gram-positive and Gram-negative bacteria. The mode of action of the bacteriocin was identified as bactericidal.