Objective To observe the therapeutic effect of spinal cord injury(SCI)by transplantation cryopreserved neural stem ceils(NSCs).Methods 45 Wistar rats were randomly divided into three groups.with 15 rats in each group.Transplantations were carried out two days after SCI,group A:0.9% saline water,group B:NSCs,group C:cryopreserved NSCs.After the transplantation,immunohistochemical and tissue incision were appeared to detect the survival and differentiation of the transplanted ceils in nivo,and the methods of BBB and oblique plate were used to estimate the recovery of function.Results Group B and C all had active NSCs except group A.The injuried spinal cord A[(3.9±0.1)mm2],B[(1.2±0.3)mm2]and C[(1.1±0.3)mm2],there was an variance in the three groups (F=423.949,P＜0.01),BBB test:group A[(2.0±0.5)mark],B[(16.4±0.8)mark]and C [(16.0±1.4)mark],there was an variance in the three groups(F=970.157,P＜0.01),the oblique plate test:group A[(31.3±2.9)degree],B[(46.8±2.1)degree]and C[(46.5.4-2.4)degree],there was an variance in the three groups(F=151.099,P＜0.01),the tests demonstrate there were no variance in group B and C(all P＞0.05),there was no variance in living rate between the cryopreserved NSCs group [(55.9±5.2)%]and no eryopreserved[(65.1±3.4)%,t=3.334,P＞0.05].Conclusions Cryopreserved NSCs keep the ability of reproducdon and differentiation.NSCs is a kind of valuable cell resource for the therapy of SCI.