Lignocellulosic biomass is the most plentiful of all the naturally occurring organic compounds. Conversion of cellulosic polymers into useful products by fermentation involves two stages: firstly conversion of cellulose to glucose by cellulase, and secondly microbial conversion of the resulting glucose to products. The experiments were conducted to obtain xylanase enzyme from the Aspergillus niger strain AUMC 14230 by using corn cob (1%) as main component in fermentation media. The experiments were carried out in the laboratory of Soil, Water and Environmental Institute, Giza Egypt. To achieve this target. The best carbon source in this study is corn cob 1% concentration. The ideal nitrogen source is corn steep liquor (CSL) 3% concentration. The highest production of the enzyme was obtained when we were used modified medium (corn cob 1%, wheat bran1% and CSL 3%). The ideal environmental conditions to give highest production from both enzymes was found as: inoculum size 0.50% (v/ml), initial pH 4.5, aeration 1:5 (V_m:V_f), incubation temperature 50^oC, agitation rate 175 rpm and time course 72 hr.