Strain　825　with　α-amylase　activity　was　isolated　from　marine　samples　of　Pingtan　sea　and　Tai　wan　strait　and　identified　as　Bacillus　sp.　by　16S　rDNA　sequence　analysis.　Amylase-producing　medium　of　strain　825　was　optimized,　and　the　optimum　conditions　were　as　follow:　soluble　starch　2.0%,　yeast　extract　0.5%,　peptone　1.5%,　initial　pH7.0,　fermentation　period　60　h.　Under　these　conditions,　α-amylase　activity　increased　from　46.55　U/mL　to　77.44　U/mL,　66.36%　higher　than　before.　Furthermore,　the　α-amylase　properties　were　analyzed　and　the　results　were　obtained.　The　optimal　reaction　temperature　of　α-amylase　was　70,　and　more　than　90%　of　its　maximum　activity　was　maintained　after　incubation　for　1　h　under　30-50.　The　optimal　reaction　pH　was　7.0,　and　more　than　70%　activity　was　retained　after　incubation　for　1　h　in　the　pH　5.0-9.0.　It　indicated　that　this　α-amylase　had　a　wide　pH　tolerance　range.　©　2017,　Editorial　Office　of　Journal　of　CIFST.　All　right　reserved.