Abstract: In order to observe the antibacterial activity of Forsythia suspense extract on Staphylococcus aureus, Escherichia coli, Salmonella sp. and other pathogens, the antibacterial activities of F. suspensa extract on S. aureus, E. coli and Salmonella sp. in vitro were determined by using tube double-dilution method. After mice were administrated with the same concentrations of pathogens by intragastric administration, mice were treated with F. suspensa extract to determine the number of bacteria in the duodenum, jejunum, ileum and cecum of mice. The results showed that F. suspensa extract had inhibitory effects on S. aureus, E. coli and Salmonella sp. in vitro and in vivo. And the inhibitory effect on S. aureus was the strongest and that on Salmonella sp. was the weakest. The mortality of mice induced by pathogens was significantly reduced by perfusing F. suspensa extract. In conclusion, F. suspensa extract had obvious inhibitory effects on S. aureus, E. coli, Salmonella sp. and other common pathogens in vivo and in vitro.