To search for novel cancer preventive agents, we assessed the quinone reductase (QR)-inducing activities of medicinal herb extracts in cultured murine hepatoma cells (hepalclc7 cells). Among 216 herb extracts tested in this study, 8 kinds of herbal extracts were found to induce QR activity in hepalclc7 cells by more than 2-fold when used at the concentration of 25 $mu extrm{g}$/$mell$. The methanol extracts of Aster koraiensis NK and Pulsatilla koreana Nakai induced QR by 252 and 223 % , respectively, at the concentration of 25 $mu extrm{g}$/$mell$. Most of the herbal extracts with QR inducing-activity increased the enzyme activity in a typical dose-dependent manner. The QR activity in BP$^{r}$ cl cells was induced move than 50 % by the extracts of Pulsatilla koreana Nakai, Inula helenium, Physalis alkekengi var, francheti (Masters) Makino, Chrysanthemum zawadskii var. latilobum Kitamuva, Auemisia keiskeana Miquel, Chfsanthemum boreale Makino. In conclusion, hlsatilla koreana Nakai, Aster koraiensis N.K, and Chfsanthemum zawadskii var. iatilobum Kitamura, which showed relatively high QR induction, merit further animal study to evaluate their potential as cancer preventive agents.