Mutagenic activities of extracts from the filtrate of the cultured broth (PI-I), mycelia (pI-II), and the fruiting bodies (PI-III) of Phellinus igniarius were examined by Ames/Salmonella tests. No mutagenic activity was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PI-I, PI-II, and PI-III showed inhibitory effects on the mutagenic activities by the directly-acting mutagens, 4-nitro-ο-phenylenediamine(NPD) and sodium azide (<TEX>$NaN_3$<TEX>), and also by the indirectly-acting mutagens, 2-aminofluorene (2-AF) and benzo[a]pyrene (B[a]P). These results suggest that P. igniarius possesses some antimutagenic activity and may contain some chemopreventive agents.