Abstract: The residues from xylo-oligosaccharides production was applied for β-mannanase preparation instead of wheat bran, and effects of different kinds and ratio of carbon sources, inducer, nitrogen sources and loading on solid state fermentation for β-mannanase preparation by Aspergillus niger were investigated in this work. Residues of xylo-oligosaccharides production could be instead of wheat bran partly for β-mannanase preparation. Solid state fermentation of residues of xylo-oligosaccharides production and bran by A. niger for five days, which the mass ratio of residues of xylo-oligosaccharides production to wheat bran was 4:6, 2% of ammonia sulfate and 3% of konjac flour loading in the medium, the β-mannanase activity and β-mannosidase activity were 341.8 and 7.02 μmol/(min·g), respectively, and soluble protein content was 8.40 mg/g.