Objective To investigate the effect and mechanism of FTY720 in protecting the motor nerve function in rats with acute spinal cord injury (ASCI).Methods A model of ASCI in the rat was established using Allen' s method.The rats were divided into five groups according to random number table:Group A (normal control group,n =6),Group B (sham group,n =27),Group C (ASCI group,n =27),Group D (FTY720 systemic treatment group,n =27) and Group E (FTY720 topical treatment group,n =27).After treatment,each group was observed for the changes of lymphocytes in peripheral blood and topical spinal cord tissue,BBB score,pathological changes of spinal cord tissue and expression intensity of glial fibrillary acidic protein (GFAP).Results After ASCI in rats,the infiltration of local T lymphocyte subpopulations CD3,CD4 and CD8 was promoted,but the number of peripheral blood T lymphocyte subpopulations CD3,CD4 and CD8 was decreased.After FTY720 therapy,both local and peripheral blood lymphocytes were reduced in number and the decrease of peripheral blood lymphocytes in Group E was between Groups C and D.BBB score,pathologic observation and GFAP staining showed a neuroprotective effect of FTY720 and better motor nerve function recovery in Group E than in Groups C and D.Conclusions FTY720 therapy facilitates motor nerve function recovery.Local FTY720 application reduces peripheral blood lymphocytes and lowers the incidence of infection.