From the carpophores of 'Coriolus sanguineus' Fr., a bright-red, wood-rotting fungus, which were collected at Suwon, an antibiotic component was isolated as red crystal and identified as cinnabarin by UV and IR spectra. The antibiotic activities against five bacteria and three fungi were determined. It showed considerably high activity against 'Bacillus subtilis' ATCC 6633 and'Bacillus maceraus' and also against all the three fungi tested. And from this fungus a sterol was isolated and identified as ergosterol by cochromatographing with four authentic sterols.