Objective:To investigate the changes of blood coagulation and fibrinolysis in patients with acute craniocerebral injuries (ACI) and to assess their relationship with patients’ diagnoses and prognoses.Methods: A prospective study was performed using 528 ACI patients and 257 healthy controls taking a physical examination.The prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen (Fg),thrombin time (TT),platelet (PLT),and D-dimer (D-D) were observed within 6 h after injury.Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) were also employed and the statistical analysis was performed.Results: The incidence of abnormal blood coagulation and fibrinolysis in our group was 80.49% (425/528),with the abnormal indicators from high incidence to low were:D-D>PT>Fg> APTT >PLT>TT.(2) The levels of PT and D-D in ACI patients were significantly different from those of the control group (P<0.05);their levels increased with the aggravation of the severity of the injuries.Fg levels in the severe and moderate ACI patients were significantly different from that in the control group (P<0.05); there were no significant differences between the moderate inury group and the slight injuy group or between the slight injury group and the control group.The levels of APTT and TT were significantly different between the severe injury group and other groups(P<0.05).PLT levels were similar in all the groups.(3) Patients of GOS 1 and 2-3 had significantly increased PT,D-D levels and decreased Fg level compared with patients of GOS 4-5.Conclusion: ACI patients have abnormal coaculation and fibrinolysis function early after injury.PT,D-D and Fg are sensitive indices and may be helpful for early prediction of the injuries and prognoses.