Abstract: Objective To observe the effect of astragalus polysaccharide on the proliferation of neural stem cells through FLK-1/PI3K/AKT signaling pathway.Methods neural stem cells were randomly divided into control group, APS (5%) group, APS (5%) +LY294002 group, LY294002 group,we detected the expression of Nestin and Brdu；Testing the cell proliferation by CCK-8;the content of VEGF，Flk-1 by Elisa，and the protein expression of Flk-1、PI3K、p-Akt by Western blot. Results The proliferation of neural stem cells in APS group and LY294002 group were significantly different (P < 0.05), APS can improve the proliferation of neural stem cells after LY294002 intervention, and increase the content of VEGF, FLK-1 and FLK-1, P-Akt and PI3K protein expression (PC).Conclusion APS group can promote the proliferation of neural stem cells，maybe relation with improve the content of VEGF,FLK-1,promote the expression of FLK-1 protein expression, Akt phosphorylation, activate PI3K/AKT signaling pathway, regulate the downstream target genes of PI3K/AKT signaling pathway.

Key words: VEGF, FLK-1, PI3K, P-Akt, proliferation