Progressive hemorrhagic injury (PHI) can be divided into coagulopathy-related PHI and normal coagulation PHI.Coagulation disorders after traumatic brain injuries can be included in trauma-induced coagulopathy (TIC).Some studies showed that TIC is associated with PHI and increases the rates of disability and mortality.In this review,we discussed some mechanisms in TIC,which is of great importance in the development of PHI,including tissue factor (TF) hypothesis,protein C pathway and thrombocytopenia.The main mechanism in the relation of TIC to PHI is hypocoagulability.We also reviewed some coagulopathy parameters and proposed some possible risk factors,predictors and therapies.