Objective To observe the effect of Nogo-p4 on process growth of bipolar astrocyte differentiated from neural stem cells (NSCs). Methods Neurospheres were collected by suspension culture of cells obtained from spinal cords of 4 Wistar rats born in 24 hours. Immunofluorescence method was used to identify NSCs and detect expression of glial fibrillary acidic portein (GFAP) after NSCs differentiated. The NSCs were divided into groups A and B. FBS was added to group A and FBS+Nogo-p4 was added to group B to initiate glial differentiation. The process length of bipolar astrocytes was measured. Results Seven days after differentiation, bipolar astrocytes were observed in both groups. The length of the process on bipolar astrocyte in group B was shorter than that in group A significantly. Conclusion The process growth of bipolar astrocytes differentiated from NSCs derived from the spinal cord of rats is inhibited significantly by Nogo-p4.