Abstract: The flavonoids of Emilia sonchifolia were firstly extracted by 70% alcohol-water and then petroleum ether were used to eliminate the pigment or other ingredients inside.The Emilia sonchifolia flavonoid extracts were purified by the polyamide thin layer chromatography(TLC)(the developing solvent is n-butyl alcohol:H2O:acetic acid=10:5:1)or by polyamide column(70% aqueous ethanol as the eluent).The results of TLC(rutin as control)and flavonoid identification experiments showed that the the Emilia sonchifolia flavonoid has a similar components with rutin flavonoids and higher purity.The Emilia sonchifolia flavonoid showed stronger antibacterial activity against Staphylococcus aureus and weaker antibacterial activitiy against Escherichia coli andB acillus subtilis.

Key words: Emilia sonchifolia extracts, flavonoids, antibacterial activities