Bacillus　amyloliquefaciens　alpha-amylase　(BAA)　is　one　of　well-known　midrange　thermostability　amylases　that　are　widely　used　in　food　and　washing　processes.　However,　the　improvement　of　its　catalytic　properties　by　molecular　modification　is　still　lagging.　To　improve　the　activity　of　alpha-amylase　BAA,　mutants　BAA28　and　BAA294　are　constructed　via　error-prone　PCR　and　purified　by　column　chromatography　in　the　present　study.　The　catalytic　efficiencies　(K-cat/K-m)　of　BAA28　and　BAA294　are　2.42　and　2.73　mL　mg(-1)　s(-1),　which　are　43%　and　61%　higher　than　that　of　the　wild-type　BAA,　respectively.　Their　specific　activities　are　also　increased　by　40%　and　62%,　respectively,　with　no　apparent　changes　of　optimum　temperature　and　pH.　Homology　modeling　and　molecular　docking　analysis　suggest　that　the　reduced　steric　hindrance　is　an　important　factor　that　enhances　catalytic　efficiencies　and　specific　activities　of　the　variants.　These　results　may　deepen　the　understanding　of　the　mechanisms　underlying　the　effects　of　each　mutation　on　the　catalytic　efficiency　of　BAA　and　facilitate　the　construction　of　potent　BAA　mutants.