Abstract: In this study,chitinase(EC 3.2.1.14)was purified from the shell membrane of Procambarus clarkii by ammonium sulfate fractionation and column chromatographies with Sephadex G-100,Phenyl Sepharose 6-Fast Flow and DEAE Sepharose-Fast Flow. The specific activity the chitinase of 44.93 U/mg and the purification multiple the enzyme was about 16.28 times. which was a single subunit protein. The molecular weight of the chitinase was 37.7 kDa with SDS-PAGE and flight mass spectrometry. This purification method of the experiment is feasible and provides a basis for the study of subsequent enzymatic properties.