Abstract: The fibrinolytic component (FC) separated from the homogenate of abdomen of Tabanus quinquecinctus Ricardo was showed to possess both fibrinolytic enzyme and plasminogen activator activities. After ammonium sulphate precipitation,Sephadex G-75 gel filtration, Fibrin-Sepharose 4B affinity chromatography and elution from eleetrophoresis, it appeared as a single band corresponding to molecular weight(MW) of approximately 40kD on SDS-PAGE and its isoelectric point was about 4. 5 on IEF. Its optimal reaction pH was 9.0 and optimal reaction temperature was 28℃. The activity of FC was totally lost after incubation at 37℃ for two hours and could be inhibited byCa²⁺, Mn²⁺, Cu²⁺, Zn²⁺, Hg²⁺and PMSF.

Key words: Tabanus quinquecinctus Recardo, fibrinolytic component