Objective To study the effects and mechanisms of Astragalus Polysaccharides (AP) on the proliferation and osteogenic differentiation of MC3T3-E1 cell line. Methods MC3T3-E1 cells were cultured in different concentrations of AP (0, 5, 10μmol/L) for the intervention. The cell viability was detected by MTT method on the first, third, fifth, and seventh day; and cells were stained with ALP and Alizarin Red, and real-time PCR were used to detect the mRNA levels of osteogenic differentiation-related markers, including Runt-related transcription factor 2 (Runx2), β-catenin (β-catenin), and osteocalcin (Osteocalcin), Collagen I (Collagen I); Western blot was used to detect the expression levels of β-catenin, Osteocalcin, and Runx2 proteins, and immunofluorescence was used to detect the nuclear translocation of β-catenin. Results The addition of 5 and 10μM AP could effectively promote the proliferation of MC3T3-E1; at the same time, it could also increase the positive rate of ALP and Alizarin Red staining, as well as β-catenin and Osteocalcin, Runx2, Collagen I mRNA expression levels (P<0.05); Western blot results also showed that AP can effectively promote the expression of β-catenin, Osteocalcin, Runx2 protein (P<0.05), and promote β-catenin into the nucleus. Conclusion AP can promote the proliferation and osteogenic differentiation of MC3T3-E1. The potential mechanism may be related to the up-regulation of osteogenic markers and the promotion of β-catenin into the nucleus. [ABSTRACT FROM AUTHOR]