Objective: Transplantation of stem cell, especially neural stem cell, has been proven effective in treating nervous system diseases in animal models, which provides new hopes for recovery of nerve functions in patients suffering from various nervous system diseases. Multiple studies have been conducted on the role of neural stem cells in repairing nerve functions, and several hypotheses have been proposed to explain how the stem cells or neural stem cells acts to recover nerve function. Data sources: We searched Medline for English articles from January 1997 to August 2003 with stem cell, neural stem cell, bone marrow stromal cell, stroke, ischemic injury, nervous system disease, and neurotrophic factor as the keywords. We also searched Wangfang database for Chinese articles with the same keywords from January 2003 to December 2004. Study selection: The articles found in these two databases were primarily screened with the inclusion criteria as follow: the subjects should be animals or human; and the study should be the basic and/or clinical researches on(neural) stem cells. Data extraction: Totally 72 English and Chinese articles were found in the two databases, among which 14 articles were closely associated with the present study and 10 were indirectly related. Eight articles were excluded for repetition in the contents. Finally 16 articles were included for analysis. Data synthesis: The full text of the articles were reviewed and summarized. The results of these articles suggest that neural stem cells are valuable in treating cerebral vascular diseases, brain and spine injury, nerve degeneration diseases, and peripheral nerves diseases. Conclusion: Stem cells, especially neural stem cells, play active roles in treating nervous systeme diseases such as differentiation promotion, nerves nourishing, and nerve substitute.