Abstract: In this experiment, taking the chitosan complexed with Fe3O4 as the carrier, the adsorption- crosslinking method was used to immobilize pectinase. Effects of deacetylation degree of chitosan and molecular weight on the shape of the carrier were studied, and effects of enzyme concentration, pH, temperature and time, etc. on the process of immobilization were also studied. The method of orthogonal test was used to optimize the main conditions of carrier preparation and enzyme immobilization. The results indicated that with the increases of the deacetylation degree of chitosan and its molecular weight, the carrier shows good performance. The optimum conditions for the activity of the deacetylation degree of the chitosan 95% with 200000 molecular weight, its concentration 3% , Fe3O4 to chitosan ratio 1:3, concentration of glutaric dialdehyde 3%, and addition of pectinase as 0.3 ml, with preservation rate of pectinase activity 79%.

Key words: chitosan, pectinase, immobilization