The extracts drawn out from Artemisia princeps by water was concentrated. Using this concentrate the silk and the cotton fabrics were dyed, and they were measured with the K/S value, surface color and mordant quantity in order to evaluate the dyeability and the antimicrobial activity. The results are as follows; 1. The K/S value of the silk fabric was much higher than that of the cotton fabric. And the color yield of the dyed silk fabric was most efficient for the premordanting method. 2. The surface colors on the dyed fabric depended heavily upon mordants used or mordanting methods. For all cases, the value of the dyed fabric was generally dark. For the Cr-mordant among various mordants, the chroma produced clear and the color difference was distinct when using the Fe-mordant. 3. On the other hand the amount of absorbed mordant in the silk fabric was larger than that of the cotton fabric. And the Cu-mordant was most efficient. 4. The color fastness was significantly improved when mordants were added. Cr-mordant improved best in all of the dry cleaning, wet cleaning and perspiration fastness. Iron and abrasion fastness showed over 4-5 grade regardless of any mordant. And light fastness was best in Cu-mordant. 5. The Cu-mordant showed the greatest antimicrobial activity in both of mordant treat silk and cotton fabrics.