Abstract-The time course of alterations in coagulative and fiblinolytic activities was studied in CC14-induced liver disease in mice. Liver disease was induced by administration of 20% CC14 in olive oil (p.o.). After single administration of CC14, significant prolongation of r and k values and decrease in the ma value of thrombo elastogram and apparent prolongation of PT and PTT were seen at 24 hr. Fibrinogen content decreased from 12 to 72 hr after single administration, while a mild but significant decrease in fibrinogen was observed after multiple adminis trations.The activity of factor XI II increased from 5 to 12 hr and then decreased from 24 to 168 hr after single administration.The activity of the hepaplastintest and Antithrombin III decreased apparently after single and multiple administrations. The plasminogen content and the activity of a2-plasmin inhibitor decreased severely after single and multiple administrations.These results indicate that the coagulative and fibrinolytic activities were decreased to the most lowest value at 24 or 48 hr after single administration of CC14, and the severe suppression of fibrinolysis and the mild decrease in coagulative activity were observed after multiple administrations of CC14. The reason for the different effects between single and multiple administrations on coagulative and fibrinolytic systems was discussed.