To observe the effects of different number of neural stem cells (NSCs) of intrathecal injection on partial sciatic nerve transaction (PST) in a rat model of neuropathic pain and the dorsal horn of the spinal cord, dorsal root ganglion (DRG) of glial cell line derived neurotrophic factor (GDNF) expression of. Methods : 84 adult male SD rats were randomly divided into seven groups: group sham (group I ), group PST (group II), group PST + NSCs 1×103(group III), group PST + NSCs 1×104(group IV), group PST + NSCs 1×105 (group V), group PST+NSCs 1×106(group VI), group PST+ NSCs 1×107(group VII). Three days after intrathecal injection NSCs. Record 1 days before operation, after 1, 3, 7, 14, 21 days of mechanical pain and heat pain threshold;and 7 to 21 days, immunohistochemistry and RT-PCR detection of the ipsilateral spinal dorsal horn and DRG GDNF expression. Results : Compared with I group, the pain threshold decreased 1 days after operation in group II ~VII, after 7 days, 14 days of minimum (P<0 05), IV, V, VI, VII group with the increase of NSCs content compared with group II,the pain threshold with increased gradually, seven days after the operation,The dorsal horn of the spinal cord and DRG GDNF expression was gradually upregulated (P < 005),21 days after operation, V, W, VII group with preoperative pain threshold were not statistically significant, but the expression of GDNF in V group was the highest (P < 0.05). Conclusion : Int rathecal NSCs1×105 are the most effective in alleviating PST-induced neuropathic pain in rats.