In present study, we investigated the effects of icaritin against MM activities on myeloma cell line-U266, primary bone marrow mononuclear cells (BMMCs) and CD138+ cells from MM patients in vitro and mouse xenograft model in vivo to firmly determine the role of icaritin in anti-myeloma activity, and elucidate partly the mechanism of icaritin in anti-MM effects. The gene discussed is SDC1; the disease is plasma cell myeloma.