A　strain　of　Bacillus　subtilis(BS08)　was　used　as　feed　additive　to　study　the　effects　on　intestinal　flora　of　tilapia,　especially　on　the　adherence,　colonization　and　breeding　capacity　of　spoilage　bacteria　from　intestinal　flora　of　tilapia　during　ice　storage　after　being　fed　with　Bacillus　subtilis.　At　the　same　time,　the　effects　of　BS08　on　delaying　spoilage　of　iced-storage　tilapia　was　also　studied.　Four　treatments　were　grouped　by　feeding　with　Bacillus　subtilis　and　adding　spoilage　bacteria　(Shewanella　and　Pseudomonas)　in　water　or　not.　The　influences　of　Bacillus　subtilis　and　spoilage　bacteria　on　intestinal　flora　of　iced　storage　tilapia　from　four　treatment　groups　were　determined　by　high　throughput　sequencing.　The　TVB-N　and　K　values　were　used　as　the　corruption　index　of　iced-storage　fish.　Bacillus　subtilis　showed　the　ability　to　maintain　the　diversity　of　the　intestinal　flora　of　tilapia　and　repress　the　changes　of　the　intestinal　flora　of　tilapia.　The　degree　of　colonization　of　Shewanella　in　the　intestine　is　greater　than　that　of　Pseudomonas.　Bacillus　subtilis　could　colonize　in　the　intestine　of　fish　and　inhibit　the　colonization　of　Shewanella　to　significantly　repress　the　dominant　growth　of　Shewanella.　TVB-N　and　K　value　indicated　that　Bacillus　subtilis　significantly　delayed　the　corruption　of　iced-fish.　©　2020,　Editorial　Office　of　Journal　of　CIFST.　All　right　reserved.