Abstract: Marine microorganisms contain many unknown active substances due to their complex living environment, which is a good resource to explore the application of antagonism in aquaculture. In this study, the antimicrobial spectrum of marine microbial extracts isolated from marine organisms and environment against animal pathogenic bacteria was analyzed, and the strains with antagonistic activity were screened. 27 strains of 9 species including 3 strains of Edwardsiella anguillarum, 3 strains of E.tarda, 4 strains of Aeromonas hydrophila, 2 strains of A.veronii, 8 strains of Vibrio parahemolyticus, 1 strain of V.alginolyticus, 1 strains of V.harveyi, 3 strains of Escherichia coli, 2 strains of Salmonella pullorum were used as indicator pathogens. The antimicrobial spectrum of 74 marine strains was determined by filter paper diffusion method. It was found that among the 74 marine strains, 14 strains had inhibition on Edwardsiella, 19 strains of had inhibition on the Aeromonas, 14 strains had inhibitory effect on V.parahemolyticus, 12 strains had inhibition on V.alginolyticus, 27 strains had inhibitory effect on E.coli, 24 strains had inhibition on Salmonella, but no strain could inhibit the V.harveyi strains. Among them, N-14 (Bacillus) had certain inhibitory effects on A.veronii E-12 (MIC of 10 240 μg/mL), E.coli and S.pullorum. In addition, a total of 9 marine fungi genera were found to have significant inhibitory activities against the other 8 indicator pathogens except V.harveyi.