Objective To explore the dynamic change and clinical signiticance of plasma D-damer level in patients with cerebral hemorrhage and acute craniocerebral injury.Methods 50 patients with cerebral hemorrhage and 40 patients with acute craniocerebral injury were selected,The enzyme-linked immunosorbent assay (ELISA) was used to measure plasma D-dimer level in two groups of patients after onset,and the results were compared with 40 healthy controls.Results The levels of plasma D-dimer in the patients with cerebral hemorrhage were 1.59mg/L,2.10mg/L,1.03 mg/L,0.82mg/L at 3 h,6h,12h,2d after onset,which in the patients with acute craniocerebral injury were 1.61mg/L,2.02mg/L,1.01mg/L and 0.67mg/L,respectively.And the plasma D-dimer levels were 0.50mg/L,0.49mg/L,0.47mg/L,0.48mg/L in the control group at 3h,6h,12h and 2d after onset.The levels of plasma D-dimer in the patients with acute craniocerebral injury were significantly higher than those in the control group,and the differences were statistically significant (t =9.35,12.17,4.03,3.05,all P ＜ O.05).At 7d after onset,the D-dimer levels in the cerebral hemorrhage group and acute craniocerebral injury group were 0.53mg/L,0.55mg/L,respectively,which of the control group was 0.47mg/L,there was no statistically significant difference among the three groups(P ＞ 0.05).Conclusion Cerebral hemorrhage patients and acute craniocerebral injury patients have high coagulation and fibrinolytic activity in brief increase trend,dynamic observation of plasma D-dimer level in patients with cerebral hemorrhage and acute craniocerebral injury is helpful to determine courses,condition and evaluate prognosis.