Objective: To study the growth and differentiation of superparamagnetic iron oxides(SPIOs) labeled neural stem cells (NSCs). Methods: After NSCs were cultured and subcultured from newb rat brain,they were magnetically labeled with ferumoxides (a kind of SPIOs). Growth ,differentiation and other biology properties of the cells were investigated with immunocytochemistry, transmission electron microscopy (TEM) and Prussian blue staining. Results: Nestin positive cells were found in the culture and offspring clones. NSCs could be differentiated into positive GFAP and NF200 cells in serum culture. When NSCs incubated with ferumoxides, the iron particles were seen in intracellular as well as in offspring clones. With the increase in concentration of ferumoxides (5.6-11.2 μg/ml), ferumoxides showed no significant difference effects on the growth and differentiation of NSCs. When the concentration of ferumoxides exceeded 22.4 μg/ml,there was significant difference(P＜0. 05). Conclusion: We successfully label NSCs with ferumoxides,it is useful for tracking of magnetic labeled NSCs in vivo with MRI.