Blood coagulation and fibrinolytic activities were studied in rats with hepatic injury induced by carbon tetrachloride (CCl4). Acute hepatic injury was induced by single oral administration of 0.5, 1.0, 2.0 and 3.0 ml/kg of CCl4. Experiments were performed on the parameters of blood coagulation activities (TEG, HPT, TT, PRCT, PT, PTT, fibrinogen, factor XIII and AT III) and those of fibrinolytic activities (PLG, alpha 2PI) and plasma total protein, GOT, GPT, Ht, L/B ratio. All determinations were measured at 24 hr after administration of CCl4. Blood coagulation and fibrinolytic activities in rats were weakened in accordance with the dosage of CCl4 administration. Below CCl4 administration of 1.0 ml/kg, the GOT and GPT values increased in accordance with the dosage. However, with CCl4 administration of above 1.0 ml/kg, these values stayed at almost the same level. On the other hand, the relationship between the dosage of CCl4 and logarithmic values of HPT, PT, PTT, factor XIII and PLG all showed a good straight line.