Objective To investigate the effect of autophagy activation on cell proliferation in human umbilical vein endothelial cells(HUVECs).Methods HUVECs were treated with rapamycin(Rapa).Western blot assay was performed to examine the expression of protein of microtubule associated protein 1 light chain 3(LC3),Beclin 1 and unc-51-like kinase 1(ULK1).Autophagosomes were detected by transmission electron microscopy(TEM),and autophagy fluorescence was detected by monodansylcadaverine staining(MDC)assay.The effect of autophagy activation on cell proliferation was assessed by CCK-8 assay and EdU assay.Vascular formation experiments were used to detect vasculogenic ability.Results After Rapa treatment,LC3,Beclin1 and ULK1 expressions were en-hanced,while the green autophagy fluorescence expression in the experimental group was stronger than that in the control group,and autophagosomes were visible by TEM;CCK-8 and EdU results showed that compared with the control group,the cell proliferation ability was weakened and tubes formation ability was reduced after the activation of autophagy in experimental cells.Conclusion Rapa upregulates autophagy activity in HUVECs to inhibit cell proliferation under certain time.