Cornis fructus were extracted by successive extractions and then fractionated with chloroform extract to get active fractions. This study was performed to determine the cytotoxic effect of chloroform extract from Corn is fructus on NIH 3T3 fibroblasts and cancer cell lines using MTT assay. All extracts did not exhibit cytotoxicity in NIH 3T3 fibroblasts. Chloroform extract exhibited antitumor activity in A549, MDA-MB-123, B16 melanoma and SNU-C4 cells. Futher fractionation with chloroform extract was performed to obtain effective fractions. 3 fraction showed the strongest cytotoxic effect against A549, MDA-MB-123, B16 melanoma and SNU-C4 cells. These results suggest that 3 fraction of the chloroform extract from Cornis fructus possessed bioactive material of antitumorous agents.