Abstract: The antioxidant and antitumor biological activities of eight polyphenol compounds which were separated from sugarcane top were studied.The test results showed that DPPH radical scavenging activity of quercetin was significantly higher( p < 0.05) than that of positive control Trolox.Caffeic acid showed the strongest inhibiting activity on CNE2 proliferation. Quercetin exhibited the strongest inhibiting activity on SGC7901 proliferation. 2-( 3,5- Dihydroxy phenyl)- 5- hydroxy- benzofuran and quercetin possessed stronger inhibiting activity on Hela proliferation.Eight polyphenolic compounds of sugarcane top exhibited good antioxidant activities and antitumor activities,indicated that sugarcane top would be good material for health products and health foods.