Objective: To study mechanisms of growth-promoting effects of Chinese herb "Nerve regeneration factor" (NRF) on hippocampal neurons. Methods: Rat embryonic (17d) hippocampal neurons were cultured in the presence or absence of NRF (1ug/ml). Neurite length was measured and the total RNAs were extracted and purified from control and NRF-treated neurons. The fluorescent cDNA probes were prepared through reverse transcription and hybridized with DNA microarry chips. The chips were then scanned and analyzed. Results: The averaged neuritic length of neurons treated with NRF in the NRF-treated neurons was significantly longer than that in the control (P<0.01). Out of total 15866 genes examined, 249 were significantly up regulated and 316 were down regulated in NRF treated neurons. These differentially expressed genes induced by NRF include G-protein coupled receptors, signal transduction molecules, cell growth and metabolism regulating factors, cellular structure molecules, enzymes, immuno-globulins, and apoptosis signaling molecules. Conclusion: NRF promotes neurite growth and regulates gene expression of a broad range of important signaling molecules. DNA microarray analysis provides a sensitive approach for preliminary searching of the targets of NRF effects.