Objective: To observe the analgesic effect and adverse effects of APA-BCC when transplanted into spinal subarachnoid of cancer pain patients. Methods: Different doses of Alginate-Polylysine-Alginate microencapsulated bovine chromaffin cells(APA-BCC) were implanted into the spinal subarachnoid of 100 cancer pain patients; changes of pain intensity, analgesic consumption, adverse-effects and life quality were evaluated. Results: (1)The effective rate (CR+PR) and the total effective rate (CR+PR+MR) were 84% and 96% within 5 days after transplantation. (2)The analgesia period varied between 9d and 220d. (3) The life quality and satisfaction degree were improved after APA-BCC transplantation. (4) There were no severe adverse effects observed. Conclusion: Transplantation of APA-BCC into spinal subarachnoid has long-term analgesic effect on cancer pain.