Objective To explore the expression change of death associated protein kinase(DAPK)and therapeutic time window for traumatic brain injury in rats.Method The traumatic brain injury models of rats were achieved by free drop impact model.The adult rats were randomly divided into normal control,sham-operation and TBI groups.Samples of"TBI group were acquired at the time point of2h,8h,24h,48h and 72h after brain injury.Pathological changes of injured neurons were demonstrated by H-E staining,the expression of DAPK mRNA W8.8 detected by RT-PCR,relative quantitation of neuron apoptosis Wa$detected by TUNEL.Results At the Sh after brain injury,the expression of DAPK increased evidently and neuron apeptosis Wag detected.The expression of DAPK and quantitation of neuron apeptosis reached peal[at the 24h after injury.Conclusion These obaervatiorm showed that the expression of DAPK in the cerebral tissues reached peak at the 24h after injury.The optimum therapeutic time window wag 24h after injury.