BACKGROUND:: Differentiation of neural stem cells (NSCs) was mediated by many environmental factors. Several factors can induce NSCs to differentiate into neurons in varying degrees and it is now a focus on the control of NSCs differentiation. OBJECTIVE:: To study the effects of combination of basic fibroblast growth factor (bFGF) and brain-derived neurotrophic growth factor (BDNF) on the differentiation of NSCs into neurons. DESIGN, TIME AND SETTING:: The in vitro cytology observation was performed at the Neurotomia Laboratory of China Medical University in May 2008. MATERIALS:: Three adult male SD rats were provided by Experimental Animal Center of China Medical University. METHODS:: Dispositions to the rats were consistent with ethical standards of animals. The rat brain hippocampus was removed sterilely. After trypsin digestion, NSCs were cultured in serum-free medium. Cell suspension was prepared and diluted when the diameter of the fourth passage of clone sphere was 200 µm by mixture of DMEM/F12 containing 2% B27, 20 µg/L of epidermal growth factor (EGF), and 20 µg/L bFGF. Monoclonal cells were passaged. NSCs were divided into blank control, bFGF, BDNF and bFGF+BDNF groups by different growth factors added into the media. Fetal bovine serum of 0.1 volume fraction was added in blank control group. The media in the other three groups were added bFGF, BDNF and bFGF+BDNF respectively for 1 week. The concentration of bFGF was 10 µg/L and the concentration of BDNF was 200 µg/L. MAIN OUTCOME MEASURES:: Immunocytochemistry staining was used to identify NSCs as well as to detect the differentiation of NSCs into neurons. RESULTS:: The monoclonal cells expressed nestin and the differentiated cell expressed neuron specific enolase and glial fibrillary acidic protein. Compared to blank control group, the proportion NSCs into neurons in the bFGF group, BDNF group and bFGF+BDNF group were much higher (t=3.409-7.558, P < 0.05), with the highest in bFGF+BDNF group (t =7.558, P < 0.05). CONCLUSION:: Combination of bFGF and BDNF can promote the differentiation of adult hippocampus NSCs into neurons.Tong L, Xie DL, Gao H, Tong XJ. Combination of basic fibroblast growth factor and brain-derived neurotrophic growth factor influences the differentiation of adult rat hippocampus neural stem cells into neurons.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu. 2009;13(27): 5331-5335. [http://www.crter.cn http://en.zglckf.com]