Abstract: Objective To investigate the dynamic changes of plasma D-dimer (D-D) level in patients iwht intracranial progressive hemorrhagic injury (PHI) after traumatic brain injury, and evaluate its auxiliary value in process of diagnosis and treatment of acute traumatic brain injury, and the influence on the prognosis. Methods Eighty-eight patients with acute craniocerebral injury in our hospital from July, 2012 to August, 2016 were enrolled.On 24 h, d1, d7 and d15, the peripheral venous blood was prepared for the test of D-D levels, and CT was performed in all patients, and according to the CT findings, the patients were divided into control group and PHI group (the intracranial hematoma increased significantly, ≥ 25%).The influence of D-D level on the degree of brain injury and prognosis was analyzed combined with the clinical data. Results Of the 88 patients, 42 were with PHI (47.73%).The levels of DD in peripheral venous blood were significantly higher than those in the control group[24 hours, (7.47 ±6.35):(2.01 ±2.46)],[3 days, (4.06 ±3.43):(1.41 ±2.37)],[7 days, (2.73 ±3.03):(0.91 ±1.38)],[15 days, (1.77 ±3.15):(0.41 ±1.07)], P < 0.05.GCS ≤ 8 points in patients with D-D level was significantly higher, GCS ≥ 9 points in patients with low D-D level, the two groups were significantly different;The plasma D-D level was significantly higher in the death group than in the non-death group (P < 0.05).The results showed that the higher the D-D level, PHI incidence was also higher;the prognosis of patients with different D-D level was significantly different. Conclusion The abnormal increase of D-D level in patients with acute brain injury can be used as a predictive factor of PHI, and is an important index to judge the injury and prognosis of patients.