Chitosanase is important in carbon and nitrogen recycles that occur extensively in nature, and is useful in the preparation of biofunctional chitooligosaccharides. Chitosanase occurs in a variety of microorganisms, including bacteria and fungi. Transformation by genetic engineering has increased the enzyme activity and enzyme content of recombinant chitosanase. To obtain abundant chitosanases possessing high chitosanolytic activity for large-scale production of chitosan-oligosaccharide, the chitosanase of CH2 was best induced by fructose and not induced with chitosan, unlike other chitosanases. This study investigated recombinant expression of chitosanase from , and characterized the application of the recombinant enzyme for chitosan hydrolysis. Chitosanase may have important industrial applications in the utilization of the enormous chitosan substrates. Mass spectrometry (MS) and thin-layer chromatography (TLC) were used to analyze the enzymatic products. The molecular weight of the recombinant chitosanase was estimated to be 29 kD using SDS-PAGE. The specific activity of crude enzymes was 133.60 U/mg. The specific activity of the purified chitosanase was up to 338.08 U/mg. The optimal pH and temperature of the purified chitosanase was 50℃ and 4.5, respectively. The values with soluble chitosan as a substrate were 5.48 mg/mL and 24.39 (μmol/mg)·min^-1, respectively. Fe²⁺, K⁺, Na⁺, Li⁺, Ca²⁺, and especially Mn²⁺ enhanced the enzyme activity of the recombinant chitosanase. Whereas, Ag⁺, Mg²⁺, Hg²⁺, EDTA, EGTA, and SDS inhibited the enzyme activity, and the other metal ion tested had no effect on enzyme activity. This characteristic of the recombinant chitosanase was better than the chitosanase of CH2. Furthermore, the enzymatic production of chitooligosaccharides from chitosans of various deacetylation degrees ranged mainly from chitobiose to chitopentamer, and the enzymic products contained 2-10 degrees of polymerization of chito-oligosaccharide after the recombinant chitosanase hydrolysis, but no monose. These results indicated that the enzyme was an endo-type chitosanase and a typical acidic metalloproteinase, which might be a good candidate for biotechnological application in producing chitooligosaccharides.