The antibacterial activity of the ethanol extract of Cornus officinalis against some bacteria related to foodborne illness and food spoilage was investigated. In the case of the disc diffusion assay, clear zones due to the inhibition of proliferation by Cornus officinalis extract were 8.5~18.3 mm at $4,000{mu}g/disc$. The inhibitory effect of Cornus officinalis was as follows: Escherichia. coli ${geq}$ Listeria monocytogenes ${geq}$ E. coli O157:H7 > Bacillus cereus > Staphylococcus aureus > Pseudomonas aeruginosa > Salmonella typhimurium. In addition, the MIC of Cornus officinalis extract toward B. cereus was the lowest at 1,000 ppm. The extract inhibited the growth of E. coli, L. monocytogenes, E. coli O157:H7, and Bacillus cereus throughout the growth stage. However, the growth of P. aeruginosa, S. aureus, and S. typhimurium was only inhibited by the extract during the lag phase. The constituents of all cells tested were released, especially E. coli and E. coli O157:H7. Observation of the cells using SEM demonstrated a morphological change and disruption of cells in response to treatment with Cornus officinalis extract. Based on these findings, the ethanol extracts of Cornus officinalis showed strong antimicrobial activity against all tested bacteria, indicating that Cornus officinalis can be a useful natural antimicrobial reagent.