Objective：To identify a strain of bacterium (numbered ZJ8112) isolated from the sediments of the East China Sea and study its antibacterial activity.Methods: The ZJ8112 strain was subjected to phenotypical study,salt-aggregation test and 16S rDNA sequence analysis; the sequence analysis result was searched in the GenBank to determine its characteristics.The antibacterial activity of strain ZJ8112 was tested using the following as the indicator bacteria: Pyricularia oryzae,Bacillus subtilis,Escherichia coli,Saccharomyces cerevisiae,Candida albicans and Cladosporium cucumerinum.Results: We found that the ZJ8112 was a G+ bacterium and had central spore.Salt-tolerant study showed that the optimum salt concentration was 10% and it belonged to moderate halophile.Analysis of the 16S rDNA gene showed high similarity (99%) to the Bacillus subtilis F121112.The 16S rDNA sequence of strain ZJ8112 had been submitted to GenBank (accession number: EU100745).The cultural and phenotypical characteristics demonstrated that ZJ8112 is a strain of Bacillus.Bioactivity study showed that ZJ8112 had potent inhibitory activity on Escherichia coli and Pyricularia oryzae.Conclusion: ZJ8112 is a halophytic bacterium with an optimum salt concentration of 10%.ZJ8112 can strongly inhibit the Escherichia coli and Pyricularia oryzae,showing a potential role for antibiotics development.