A　pectinase-producing　strain　G1　was　isolated　from　rotten　fruit　by　the　methods　of　transparent　circle　observation　and　pectinase　activity　determination.　Strain　G1　was　identified　as　Aspergillus　niger　based　on　its　morphological　observation　and　analysis　of　18S　rDNA　sequence.　Through　single-factor　experiments,　the　optimum　medium　contains　(g/L):　orange　peel　32,　bran　10,　(NH4)2SO4　22,　Na2HPO4·12H2O　8.4,　KH2PO4　1.4,　MgSO4·7H2O　1.0,　Ca2Cl　0.1,　FeSO4·7H2O　0.1,　ZnSO4·7H2O　0.1,　initial　pH　6.5.　The　conditions　for　optimum　pectinase-producing　were　the　combination　of　the　inoculums　size　9%,　medium　volume　50　mL/250　mL,　temperature　32°C　,　and　shaking　at　180　r/min　for　7　days.　Under　these　conditions,　the　pectinase　activity　which　reached　up　to　270.4　U/mL　was　improved　by　8.7　times　compared　with　original　pectinase　activity.