Objective To investigate the effect and mechanism of astrocytes on the proliferation of neural stem cells (NSCs) in adult and juvenile hippocampus microenvironment.    Methods  Hippocampal astrocytes were isolated and cultured from 5 female SD rats at day 1 and week 30 postnatal, respectively; Embryonic hippocampus NSCs was isolated and cultured from 1 SD rat at day 15 of gestation; Conditioned astrocyte culture medium（CM） was collected for NSCs culture; Flow cytometry and CCK-8 were used to detect the proliferation of NSCs cultured in CM. Colony stimulating factor 1 (CSF-1) with differential expression was screened by mass spectrometry after cultured astrocyte CM. Western blotting and ELISA were used to verify the result  of mass spectrometry. Immunofluorescence, flow cytometry and CCK-8 were used to detect the proliferation of NSCs treated with different concentrations of CSF-1 recombinant protein （20 μg/L,  100 μg/L, 1 mg/L and 5 mg/L）.    Results  Compared with the adult group, the CM of hippocampal astrocytes in the young group could promote the proliferation of NSCs(P<0.01); Compared with the conditioned medium of hippocampal astrocytes in the juvenile group, the expression of CSF-1 in the hippocampus of the elder group was significantly up-regulated(P<0.01); At 20 μg/L, CSF-1 promoted the proliferation of NSCs(P<0.01), and 5 mg/L CS-1 inhibited significantly the proliferation of NSCs(P<0.01).     Conclusion The secretion of CSF-1 by astrocytes in hippocampal microenvironment can regulate the proliferation of NSCs with the development of the times.