Five cytotoxic and antioxidative flavonoids were isolated from the stem bark of Cudrania tricuspidata by consecutive purification using HP-20, silicagel and prep-HPLC. They were identified as taxifolin, orobol, eriodictyol, dihydrokaempferol and steppogenin by means of spectral studies. The antioxidative activities (IC_(50)) assayed by TBA method of these compound 1∼5 to were 6, 3, 3, $gt;50, and 10 ㎍/㎖, respectively. The effect on the growth inhibition (IC_(50)) of these compounds against P388 cell line were found to be 0.18, 3.3, 15 and 6.2 ㎍/㎖, respectively in the order of compound 2 to 5.