To provide a novel cell proliferation inhibitor (agent for cancer prevention/therapy) that can substitute as conventional well-known antitumor agents.SOLUTION: A cell proliferation inhibitor contains sweet basil extract.SELECTED DRAWING: None【課題】従来公知の抗腫瘍剤に代替しうる新規な細胞増殖抑制(癌の予防・治療剤)を提供する。【解決手段】スイートバジル抽出物を含む、細胞増殖抑制剤。【選択図】なし