The early stage of the state in which coagulation or fibrinolytic pathway is activated has been difficult to estimate. It has become possible to detect disseminated intravascular coagulation (DIC) at an early stage due to the development of highly sensitive methods which quantitate so called "molecular markers". Herein, to evaluate the clinical usefulness of plasmin-alpha 2-plasmin inhibitor complex (PIC) and tissue factor activity in plasma were examined. The first time, monitoring the plasma levels of PIC might be useful for the diagnosis of a pre-DIC condition and for effective control of therapy. We believed that combination assay for both PIC and D dimer will be adequate to differentiate whether the hemostatic abnormalities are induced mainly by DIC or hepatic insufficiency. Recently, new clinical usefulness of PIC has been reported. The PIC/thrombin-antithrombin III complex ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without it. The tissue factor is a major activator of the coagulation cascade and may play a role in initiating thrombosis. A simple chromogenic substrate assay for the quantitation of tissue factor activity in plasma samples was developed. Abnormally high levels were found in 80% of the patients with DIC, predominantly in patients with non-hematological solid tumors and acute leukemia. Serial determinations of plasma tissue factor demonstrated that plasma tissue factor changes immediately with the course of DIC. Plasma tissue factor did not correlate with hemostatic markers of DIC such as thrombin-antithrombin III complex, PIC, FDP D-dimer. Tissue factor activity correlated well with membrane anchoring region of tissue factor protein levels. Tissue factor activity correlate with tumor necrosis factor alpha levels in patients with non-hematological solid tumors without hepatocellular carcinoma. These findings suggest that the plasma tissue factor is potentially valuable for monitoring the progress of DIC in a limited population of patients.