Comparative investigation concerning gelfiltration as well as haemostaseologic analysis of venoms and venom fractions of some snakes (elapidae and viperidae) have shown that in elapidae an inhibition of coagulation is dominant whilst in viperidae the stimulation of coagulation is of importance. Our investigations produce a basis to select substances for activation of coagulation and substances for inhibition of coagulation. Under pharmacological viewpoints the data may produce information to use snake fractions for anticoagulation or for procoagulant therapy in bleeding tendency.