摘要Objective: To study the altering rule of coagulation function at molecular level in patients with secondary brain injury (SBI).Methods: Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were studied in 32 patients 1, 2, 3 and 7 days after craniocerebral injury. Repeated cranial CT scans and platelet counts were made simultaneously. Same measurements were done in 30 normal adults except CT scan.Results: No obvious difference was found in age, sex and platelet count between the injured and the normal groups. TFPI/TF decreased markedly in the first week after injury in patients with SBI, but only decreased on the 7th day in the patients without obvious SBI. For the patients who developed delayed intracranial hematoma (DIH) or hematoma enlargement, TF rose only 1 and 2 days after injury, but TFPI had a tendency to rise again after a fall on the 3rd day. For those patients who developed no DIH, TF rose all the time within the 1st week.Conclusions: Decrease of TFPI/TF for a long time, especially within 3 days after injury, may be one of the most important reasons for SBI. High expression of TF for a relative short time and increase of TFPI after a fall within 3 days may be one of the important reasons for DIH or hematoma enlargement.