Abstract: The substrate specificities of TMVFg (a fibrinogenase from Trimeresurus mucrosquamatus venom),OhS1 (a fibrinogenase from Ophiophagus hannah venom) and sv-PA (a specific plasminogen activator from Trimeresurus stefnegeri venom) on five chromogenic substrates were studied.Further,We studied the effects of these venom serine proteases on purified blood coagulation factors,like factor Ⅹ,prothrombin,plasminogen and protein C.The comparison studies were dealed with other venom serine proteases,like Bothrops atrox venom thrombin-like enzyme (Batroxobin),Agkistrodon contortrix contortrix venom protein C activator (ACC-C) and Vipera russelli venom factor V activator (RVV-V),and also with trypsin,thrombin,urokinase.Immunochemical study by ELISA proved that anti-sv-PA antibodies cross-reacted with other venom serine proteases but did not cross react with thrombin,urokinase and t-PA.We also compared the sequences of these serine proteases.Based on the results of substrate specificity,immuno-chemistry and sequence comparasion,the paper give the discussion on the structure function relationship of these serine proteases.