Hot water extract from mugwort (Artemisia asiatica nakai) leaves and tea inhibited the growth of Bacillus subtilis by adding to the nutrient broth 1.0% and 0.5% concentration, respectively. Among the important compounds that contributing mugwort like flavor to the mugwort leaves and tea were considered, authenic compound of thujone, caryophyllene and farnesol showed bactericidal effect for Escherichia coli, Enterobacter aerogenes, Vibrio paraheaemolyticus, Psudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus when teste by paper disc method ( 8 mm diameter). The mixture of caryophyllene and farnesol was more bactericidal effect for various bacteria than the mixture of thujone, caryophyllene and farnesol was more bactericidal effect for various bacteria that the mixture of thujone, caryophyllene and farnesol or each compounds . Especially, the mixture of caryophyllene and farnesol showed strong bactericidal effect (diameter of inhibition zone>40mm) for Vibrio parahaemolyticus , Enterobacter aerogenes and BAcillus subtilis.