Obvious　antagonistic　effects　of　Bacillus　subtilis　BS08　against　spoilage　bacteria　(Shewanella　putrefaciens,　Pseudomonas　fluorescens,　Psychrobacter　immobilis)　isolated　from　Pseudosciaena　crocea　were　found　by　the　dural　culture　methods.　Fermentation　filtrate　of　Bacillus　subtilis　BS08　showed　strong　antibacterial　activity　on　Psychrobacter　immobilis.　Single　factor　experiments　and　Response　surface　methodology　were　used　to　optimize　the　fermentation　medium　for　production　of　antibacterial　substances　by　BS08.　The　results　showed　that　the　optimal　medium　ingredients　were　comprised　of　glucose　14　g/L,　yeast　extract　14　g/L,　MgSO4　1　g/L,　with　20%　additive　volume　of　fermentation　filtrate,　and　the　bacteriostasis　rate　reached　67.2%　after　incubation　for　24　h,　improved　20.8%　than　using　initial　fermentation　filtrate.