Abstract: Objective: To observe the analgesic effect of subarachnoid transplantation of APA microcapsulized BCCs on chronic constriction injury （CCI）rats. Methods: SD rats were randomly divided into four groups, each has ten.Normal rats were used as control group （group C）.Rats that right sciatic nerve was ligated were used as CGI group.Five to six hundred empty APA microcapsules（group APA） or 5 X 106 APA microcapsulized BCCs （group APA-BCCs） were grated into subarachnoid space of CCI rats 7 days after operation.Allodynia and hyperalgesia were measured by Von- Frey filaments and CO₂ laser dividually one to six weeks after transplantation.TH immunohistochemistry was used to judge the survial of grafted cells.ENK and DpH immunohistochemistry were done on the spinal cord.Rusults: Allodynia threshold and CO₂ pain threshold on the ligated sides of group APA-BCCs were higher than that of on group CCI and APA 7 to 42 days after transplantation, but there were no difference compared with that of group C.Immunohistochemistry showed that TH was positive on grafted BCCs, ENK and DpH were positive on many cells of the pial surface. Conclusion: Subarachnoid transplantation of APA microcapsulized BCCs can alleviate allodynia and heperalgesia in CCI rats.ENK and NE take part in this analgessiic effect.