Objective To know the role of inhibitor of DNA binding 2(Id2) in the development of neural stem cells(NSCs) in the anterior subventricular zone(SVZa) . Methods To examine the expression of Id2 in SVZa,rostral migratory stream(RMS) and olfactory bulb (OB) in E14, P0，P7, P14, P30 adult and old rat brains by reverse transcriptasepolymerase chain reaction(RT-PCR),Western blotting and immunohistochemistry. Results The expression of Id2 peaked at the area of RMS, and was less positive in SVZa and the least in OB at different time courses of developing rat brains.The expression of Id2 in the three areas in E14 were higher than that on the postnatal day, higher in OB and RMS in adult than that on P0,and remain high in old.However,the expression of Id2 in SVZa in adult was weaker than that on P0.Conclusion The expression of Id2 in the deveolpment of SVZa NSCs indicates that Id2 plays an important role in blocking the differentiation of SVZa NSCs and increasing the proliferation of SVZa NSCs.