Abstract: Catalysis kinetics characterization of douchi fibrinolytic enzyme（DFE）is studied.The results show that:the relative molecular weight is 41 970,the optimal reaction pH is pH7.0,DFE’s activity is the stablest at the pH range of 78,relatively stable at the pH range of 8-10,0 under the pH 4;the optimal reaction comperature is 41 ℃,enzyme activity is higher at the comperature range of 37-45 ℃;the stability of conservation is best at 15 ℃;Hg2+could remarkably inhibit DFE’s activity,Fe3+and Li+ could enhance it.When casein is used as a substrate,the reaction catalyzed by DFE is inhibited by the substrate.

Key words: douchi fibrinolytic enzyme； catalysis kinetics； study；