The aim of study was to elucidate dyeability and antimicrobial and antifungal activity of silk fabrics dyed with Sophora Radix extracts according to different mordants. Dyes were extracted from Sophora Radix using ethanol. Then, silk fabrics were dyed with extracts two times by post-mordanting method in which the extract was 60%(owf), the mordant was 3%(owf), L.R was 1:20, the temperature was $60~60^circ{C}$, the time of dyeing was 60min., and the time of mordanting was 60min. The dyeability was evaluated by surface color, K/S values and durability of dye. The skin microorganisms used in this study was S. sureus, B. subtilis, S. epidermidis, P. acnes, P. aeruginosa, E coli, A. niger, C. albicans and T. mentatrophytes. The results are as follows; 1. When mordants were added, K/S value of silk dyed was not improved much and surface color was 2.2Y to 8.8Y in H(hue) value which indicated greenish yellow to raddish yellow 2. The color fastness tests to light, perspiration, dry-cleaning, rubbing, and stain fabric washing show 4~5th degree which were valuated excellent. The color fastness to fade washing was improved to 3~4th degree by addition of $K_2CrO_7$ mordants. 3. Antibacterial activity of silk dyed using no-mordant as well as mordants was excellent on S. aureus, B. subtilis, S.epidermidis and P.acnes, but showed poor antibacterial activities on P.aeruginosa and E.coli such as gram negative baterials 4. Antifungal activity of silk dyed with ethanol extracts was good on A.niger, C.candida and T.mentagrophytes. Especially, on T. mentagrophytes there was no growth of fungus during 72 gous in silk dyed mordanting with $SnCl_2cdot{2H}_2O$.