The　antifungal　protein　MG-3A　was　isolated　from　Bacillus　amyloliquefaciens　MG-3,　and　was　purified　and　identified.　The　results　showed　that　antifungal　protein　MG-3A　was　likely　a　serine　protease　with　a　molecular　weight　of　similar　to　48　kDa.　The　serine　protease　exhibited　a　broad　antifungal　spectrum　and　effectively　extended　the　shelf-life　of　loquat　fruit　up　to　25　d.　The　antifungal　protein　MG-3A　showed　good　stabilities　to　temperature,　pH　and　protease　K.　Primers　were　designed　according　to　the　mass　spectrum　of　antifungal　protein　and　the　comparison　with　proteins　in　the　NCBI　database.　The　serine　protease　gene　MG-3A　from　B.　amyloliquefaciens　genome　was　isolated　and　cloned　using　PCR.　The　prokaryotic　expression　plasmid　pET28a-MG-3A　was　constructed　and　used　to　express　the　antimicrobial　protein　in　vitro.　The　SDS-PAGE　results　showed　that　the　recombinant　protein　expressed　in　Escherichia　coli　BL21　(DE3)　was　highly　soluble.　Affinity　chromatography　was　used　to　purify　the　recombinant　protein　and　its　antifungal　activity　was　evaluated.