To investigate the effect of Astragalus polysaccharides on the proliferation，apoptosis，and cell cycle of leukemia cells（Jurkat)，and to further explore its underlying mechanisms.Methods:Jurkat cells were treated with different concentrations of Astragalus polysaccharides（0，100，200，400 μg/mL).The cell counting kit-8（CCK-8) assay was used to detect the proliferation inhibition rate of each group.Flow cytometry was employed to assess cell cycle distribution and apoptosis.Real-time quantitative PCR（Real-Time PCR) and Western blot were used to detect the mRNA and protein expression of Cyclin D1，Cyclin E，Caspase 3，and Caspase 8.Results:Astragalus polysaccharides at concentrations of 100，200，and 400 μg/mL effectively inhibited Jurkat cell proliferation in a dose-and time-dependent manner（P<0.05).Flow cytometry analysis showed that compared with the control group，with increasing concentrations of Astragalus polysaccharides，the number of cells in the G0/G1 phase increased，while the number of cells in the G2/M phase decreased，and the apoptosis rate gradually increased（P<0.05).In the Astragalus polysaccharides-treated groups，the mRNA and protein expression of Cyclin D1 and Cyclin E decreased，while the mRNA and protein expression of Caspase 3 and Caspase 8 increased（P<0.05).Conclusion:Astragalus polysaccharides can effectively inhibit the proliferation of Jurkat leukemia cells and promote their apoptosis，exerting an anti-leukemia effect.The mechanism of action is related to the regulation of Cyclin D1 and Cyclin E expression，blocking the cell cycle at the G0/G1 phase，and promoting the expression of apoptosis-related genes Caspase 3 and Caspase 8.