Abstract: Objective: To study the clinical effect of neural stem cell transplantation in the treatment of inherited cerebellar atrophy (CA). Methods: The cells from human fetal cerebellum (8-10 weeks of gestation) were grown and expanded in vitro. The cultured neurospheres were then implanted into the dentate nuclei of patients by stereo tactic operation. Totally, 12 patients (7 males and 5 females with age ranging 22-62 years, mean 43 years) were treated by this operation from August 2006 to August 2008. Results: The cells of fetal cerebellum were expanded by 10⁷ folds in undifferentiated state in the culture. After the operation, no rejection was detected. Follow up, the effective rates were 58.3% after 3 months, 75.0% after 6 months, and 66.7% for 12-24 months (mean 18 months). Conclusion: the transplantation of in vitro cultured neural stem cell is a feasible and effective treatment for inherited CA, but the long term effectiveness need to be taken in consideration.