The growth of a lactobacillus named Lactobacillus brevis CGMCC 6683 in media containing inorganic salt Na2SeO3 was studied. The results showed that the bacteria biomass decreased from 108 CFU/mL to 104 CFU/mL, and the morphologies of L. brevis were damaged according to the scanning electron microscope and laser scanning confocal microscope images. Genes encoding peptide-methionine (S/R)-S-oxide reductase and thioredoxin-disulfide reductase were upregulated significantly as indicated by real-time quantitative polymerase chain reaction (qRT-PCR), it showed that oxidative stress was occurred in L.brevis while growing in the Na2SeO3 contained medium, this was in line with the malondialdehyde (MDA) content test result which accounted for the occurrence of lipid peroxidation. In conclusion, reaction between reaction active oxygen (ROS) and membrane lipids could cause membrane damages and resulted in death of cells ultimately.