Abstract:Pueraria root residue is a bulk waste obtained after processing Pueraria roots，and it is rich in the biologically active ingredient puerarin.The medium was obtained using Pueraria root residue as the main raw material，adding bran at a ratio of 8∶3 （ω/ω）and then adding 70% of the solid mass of water and an appropriate amount of inorganic salt.The solid-state fermentation was conducted at 30°C using Aspergillus niger.The degradation of the fibrous tissue of the Puerariacell wall by xylanase and CMC enzyme promotes the release of puerarin from the cell.The results showed that the maximum activity of xylanase and CMCase could be measured separately when fermented for 72 h and 96 h，respectively.When fermented for 120 h，the puerarin content in the fermented material was close to the maximum value determined through high performance liquid chromatography，which was 5.68 mg/g.Compared with the direct alcohol extraction of the Pueraria root residue，the content of puerarin obtained increased by 74.8%，achieving an efficient puerarin preparation.