Abstract: Enzymatic process was the main emphasis in replacing the acidbase method to take off the citrus segment membrane in citrus cans production. However, the cost of the enzymatic process was high and the amount of organic compounds of waste water discharged did not decrease. One stain of Aspergilluse niger with high pectinase yield was screened out using the segment membrane of citrus as the single carbon source. The optimal fermentation conditions for pectinase were found as follows: pH=7, 28℃, 0.5% glutin as nitrogen source, 6% inoculation amount. The activity of the enzyme in fermentation liquor could reach 9.32×103 U·mL-1. The enzyme produced from the membrane fermentation could take off the citrus over 2 times as the original weight. The process provided a low pollution and low cost way of taking off citrus segment membrane．