Abstract: In order to study effects on antibacterial activities of Emilia sonchifolia extracts by different solvents, the antibacterial ingredients against Emilia sonchifolia were extracted by water, 50% alcohol-water solvent and pure alcohol, respectively, and thentheir extracts were used to inhibit the growth of Bacillus subtilis, Escherichia coli or Staphylococcus aureus in this research. The results showed that water is a good solvent for extracting more ingredients from the herb, and its extracts just only showed a good antibacterial activity agcinst Staphylococcus aureus, but didn’t show a strong antibacterial activity agcinst Bacillus subtilis or Escherichia coli. 50% alcohol-water solvent is an excellent solvent for extracting more ingredients from the herb, and its extracts showed the strongest antibacterial activitly against all of the three kinds of bacterium. The pure alcohol extracts is not a good solvent for extracting more ingredients from the herb, its extracts showed a stronger antibacterial activitly agcinst Bacillus subtilis or Staphylococcus aureus, and a weak antibacterial activity agcinst Escherichia coli. It could be sure from the experimental results that 50% alcohol-water solvent is a best solvent for extracting more antibacterial ingredients from the herb.

Key words: Emilia sonchifolia extracts, different solvents, antibacterial activities