Abstract: The bamboo leaves extract was obtained by decocting with water and then deposited with ethanol to remove the sample matrix.Water extract was further extracted by four different polarity solvents i.e. petroleum ether, chloroform,ethyl acetate and n-butanol,successively.Antibacterial activity on Staphylococcus aureus and Escherichia coli of the four fractions were studied by inhibition zone method (agar diffusion method) and minimal inhibitory concentration method (MIC) comparing with ethylparaben.The results indicated that the petroleum ether,chloroform,and ethyl acetate fractions exhibited significant inhibitory effects on both kinds of bacteria.The inhibition zones of samples for test were between 9.8 and 18.4 mm and minimal inhibitory concentration (MIC) were 1.25 mg/mL,2.50 mg/mL,and 5.00 mg/mL,respectively.Finally the scavenging effect on ?OH radical of bamboo leaves extract was studied by Nit-R-Co2+ system,it was found that the chloroform and ethyl acetate fractions also possessed significant antioxidant activity,and IC50 of ethyl acetate extract was 1.06 mg/mL.

Key words: bamboo leaves extract, antibacterial activity, antioxidant activity, free radicals scavenging