Aspergillus niger KSU 23 isolate was selected as a potential producer of xylanase via a submerged fermentation technique using corn cobs as substrate. The trials for xylanase production were conducted at two concentration levels (2.5 and 3.0) of corn cobs, four different fermentation temperatures (25.0, 27.5, 30.0 and 32.5°C) and four various initial pH levels (5.0, 5.5, 6.0 and 6.5) of the culture medium for a period of 96 h. The results revealed that the A. niger KSU 23 exhibited maximum enzyme activity (62.36±1.91 IU/mL) at 3.0 % corn cobs concentration followed by (60.12±1.09 IU/mL) at 2.5 % concentration respectively at 30^oC, 6.0 pH after a period of 72 h of incubation. The comparison of the effect of different initial pH grades of culture medium exhibited that pH 6.0 had most potent role in xylanase production as compared to different other pH levels. Time scale analysis revealed that fermentation period of 72 h was the most suitable for obtaining maximum enzyme activity. Moreover a temperature of 30^oC was found to be optimum for higher yields of xylanase.