Abstract:1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) method, β-carotene bleaching method and nitric oxide (NO) method were used to determine the antioxidant activities of different extracts from Acalypha australis L.; All the extracts were evaluated for their bacteriostatic effect using microporous turbidimetry method, and three gram-negative bacteria: Escherichia coli, Pseudomonas aeruginosa, Helicobacter pylori and four gram-positive bacteria: Staphylococcus epidermidis, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus were determined in our research. The results showed all the extracts we determined had the activities of better scavenging DPPH, NO free radicals and inhibition of β-carotene bleaching. At the concentration was 2.0 mg/mL, the n-butanol extract had the strongest power to scavenge DPPH free radicals and inhibit β-carotene oxidation activity. The DPPH free radical scavenging rate was 94.60% and the β-carotene inhibition rate was 83.15%. Furthermore, the ethyl acetate extract had the strongest ability to scavenge NO radicals, and the clearance rate was 82.72%. In addition, the results of bacteriostatic experiments showed that all the extracts had good antibacterial effect, and its inhibitory effect against Gram-positive bacteria was higher than that of Gram-negative bacteria. Especially, the petroleum ether extract had the best inhibitory effect on Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus, and the minimum inhibitory concentration (MIC) values were 0.625, 0.315 and 1.250 mg/mL, respectively. In conclusion, the extracts of Acalypha australis L. have better anti-oxidation and antibacterial effects and this research was profitable for the further study of the separation of avtive compounds from Acalypha australis L..