Objective:To observe the effect of lithium on the spine cord injury (SCI) rats; to compare the neuroprotective of different does of lithium chloride on SCI rats.Methods:The models were made by the technique of the NYC method.10 rats were included in the pilot experiment at the first part.40 rats were randomly divided in to 5 groups:non treated group(5)、treated with Nacl group(5)、treated with 2mEq/kg Licl(10)、treated with 4mEq/kg Licl(10)、treated with 6mEq/kg Licl(10). All the rats were injected intraperitoneally with lithium chloride once a day for 28 consecutive days. Exam the rats by 3.0T Magnetic Resonance Imaging(MRI) at the time:post operation,one week、two weeks、there weeks 、four weeks after the operation; Study on the BBB (Basso,Beattie and Bresnahan) scale of hindlimb movements recovery in every group of rats at the forth week; Estimate spinal cord function by the latency of the motor evoked potential (MEP) and somatosensory evoked potential (SEP); At the end of the behavioral assessment,all rats were perfusion-fixed and the injured spine was made into paraffin sections for HE stain to observe the nerves.All data were expressed as mean士SD,statistical analysis was performed using SPSS 11.0 and P value of<0.05 was considered significant.