Abstract: In order to optimize the preparation process of chitosan oligosaccharide and to increase the yield of chitosan, chitooligosaccharides was used as raw material. The chitooligosaccharides was prepared by the method of microwave assisted pectinase enzymolysis and the yield was based on the reducing sugar content.Meanwhile, the optimum technological conditions weredetermined by single factor and response surface experiment. When the pectinase enzyme quantity was 2100 U/g, the microwave radiatepower was 510 W, the pH4.4 and the reaction temperature was 50℃, the degradation products of reducing sugar concentration was 1.964 mg/mL.It was increased by 12% compared to the single pectinase digestion method (1.747 mg/mL), and compared with the single microwave method (1.671 mg/mL).The ratio increased by 18%.