The anticarcinogenic effects of various food components on human cancer cells have received much attention in recent years. The precise effect and mechanisms of anticarcinogens in food materials on cancer cells have rarely been investigated. This study was carried out to determine the effects of Daucus carota L. leaf (DCL) extracts on cytotoxic and chemopreventive effect on human cancer cells. The experiment was conducted to determine cytotoxicity of Daucus carota L. leaf extracts on HepG2, Hela and MCF-7 cells by MTT assay. Among various partition layers of Daucus carota L. leaf, the ethylacetate partition layer (DCLMEA) at 500 $mu extrm{g}$/mL was shown to be most effective on MCF-7 cell lines. The four partition layers which are DCLM, DCLMH, DCLMB and DCLMH were less effecitve in inducing cytotoxicity than DCLMEA was. We also determined the induction of intracellular quinone reductase (QR) activity by adding DCL extracts on HepG2 cells. Among various partition layers of DCL extracts, DCLMH and DCLM were tested to be most effective with results such as 4.9 and 4.73 with a control value of 1.0.