Abstract: Chitin is widely distributed in nature, a nitrogen-containing polysaccharide biopolymer.Chitosan degradation products have many excellent properties, and have been used in production and other aspects of life.Chitinase is an enzyme which catalyze the glycosidic band of chitin specificitily,and its product is small fragments of chitin.This thesis describes the processes of extracting chitinase produced by HD1 bacteria. The purified enzyme was purified by precipitation,DEAE-Sephadex ion-exchang chromatography and Sephacryl S-400 gel filtration.Its molecular mass was estimated to be about 80.8KD by SDS-PAGE. The hydrolysis product assayed by TLC suggested that the chitinase catalyzed an endo-type cleavage reaction,and the hydrolysis product was water solubility.