Abstract: To investigate the antibacterial and antioxidant activities in vitro of extracts from 3 mangroves including Hibiscus tiliaceus, Avicennia marina, Aegiceras corniculatum. Four kinds of different solvent extracts were extracted by ethanol extraction and then solvent separation. The inhibition zone and minimal inhibitory concentration(MIC),were used to detect the antibacterial activities,and determined by disk diffusion method and broth microdilution method. The scavenging effect to the hydroxyl radical,superoxide radical and DPPH was detected with the oxidation of ferrous sulfate-salicylic acid,self-oxidation of pyrogallic acid system and DPPH system,respectively. The results showed that the antibacterial effect on 5 species of common pathogens were H. tiliaceus>A. marina>A. corniculatum. Inhibitory effect of water extracts was higher than other extracts significantly. All of water extracts from 3 kinds of mangroves had good bacteriostatic effect on Staphlococcus aureus(for the MIC ranging in 11.2~15.6 mg/m L). The free radical scavenging effect was DPPH>superoxide free radical>hydroxyl radical. A. corniculatum had more stronger effect on DPPH free radical scavenging,four kinds of solvent extracts of A. corniculatum had strong scavenging effects,and the ethyl acetate extract >n-butanol extract >petroleum ether extract,water extract. The results showed that the antibacterial activity of extract from H. tiliaceus was mainly in the water extract,and the ethyl acetate extract from A. corniculatum had strong scavenging effect of DPPH free radical.