Objectives : This study was carried out to investigate anti-proliferative effects on MCF-7 human breast cancer cells of Anemarrhenae Rhizoma (AR) extract. Breast cancer is the most common disease in Korean women. Despite remarkable improvements in treatment strategies against various cancers during the past 40 years. breast cancer still remains as one of the main causes of cancer mortality among women the whole world over. Methods : Be investigated the effects of AR on cytotoxicity of MCF-7 human breast cancer cells in various extract conditions (n-hexane, ethyl acetate, butanol and water fraction). Results : The extract of Anemarrhenae Rhjzoma inhibits the proliferation of MCF-7 cells in a dose dependent manner. Especially. the ethyl acetate fraction of Anemarrhenae Rhizoma showed specific Cytotoxicity on MCF-7 cells. Conclusions : In conclusion. it can be concluded that Anemarrhenae Rhizoma extract has an anti-proliferative effect on MCF-7 human breast cancer cells. Especially. the ethyl acetate fraction is most effective to inhibit proliferation of MCF-7 cells.