Rotating simplex method of optimization has been successfully used to determine the optimal conditions for extracellular pectinase production by Aspergillus niger in batch bioreactor. Maximum production of 1.132 U of polymethylgalacturonase, 1.313 U of polygalacturonase and 0.0091 U of pectinlyase was obtained at pH (controlled). 3.38; agitation rate, 483 rpm and aeration rate, 2.12 vvm. These conditions were found to be more suitable for pectinase production.