Anti-microbiological effects of xanthorrhizol, ie., extract from curcuma xanthorrhiza and extract from houttuynia cordata Thunb. against influenza virus and E. coli O157 were tested. From the influenza experiments, the effects were shown above 93 % in case of houttuynia cordata Thunb. extract, however, the effects was not shown in case of xanthorrhizol. The effects were sustained in mixtures of houttuynia cordata Thunb. and curcuma xanthorrhiza extracts. We also tested the anti-microbiological effects of hand sanitizer containing houttuynia cordata Thunb. and xanthorrhizol. The effect of hand sanitizer containing 2,000 ppm of xanthorrhizol and 500 ppm of houttuynia cordata Thunb. extract was better than that of commercialized foreign product.