The inhibitory effect of Ramaria botrytis on the mutagenicity in Salmonella assay and cytotoxicity on cancer cell were studied. Ramaria botrytis methanol extracts showed antimutagenic effects of 60~90% on B(a)P and AFB1 in S. typhimurium TA98 and TA100. These extracts showed 73~85% antimutagenicity on TA100 against MNNG. The methanol extracts with strong antimutagenic activities were further fractionated by ethylacetate and water, the ethylacetate fraction were found to be stronger antimutagen icity against MNNG than water fraction. Ramaria botrytis methanol extracts and ethylacetate fraction revealed the highest cytoxicity against HT 29 human colon adenocarcinoma cells in which cell growth was inhibited by 57~88% and 69~94% at 0.25~1.0mg/ml, respectively. These methanol extract and ethyl acetate fraction exhibited 53~79% and 66~87% inhibition against HepG2 human hepatocarcinoma cells, respectively. But water fraction showed only 10~24% inhibition. However, these extract and fractions did not show cytotoxic effect against human chang liver cells. From these results, it is considered that Ramaria botrytis has stronger antimutagenic and anticancer effects in vitro.