Abstract: The changes of ultrastructure of human embryonic lung diploid fibroblasts(HELDF) cultured in vitro in the process of cell aging were studied with scanning electron-microscope (SEM)and transmission electron-microscope(TEM).In the meanwhile,the antiaging ef-fects of Huangqi(Astragalus membranceus Bunge,or AMB)at different stages were studied dynamically.The results showed that HELDF cultured in vitro lived up to 52 generations while the culture medium containing 0.2% AMB extract made the cells live up to 77 genera-tions.Under SEM we saw that the cells changed from flat and long fusiform to ball-shaped. Their pseudopodia and microvilli increased progressively.The body of cell became smaller,its hollows deepened gradually.Under TEM the change of cells with increasing age were mainly as follows:Nucleus became smaller gradually.The hollows deepened increasingly.Nuclear membrane changed from partly fusion to totally disintegration.Heterochromatins increased while euehromatins decreased gradually.Nucleous became small and loose.Mitochondria and their eristae decreased.The stroma became cohesive,swollen and vaeuolized.Rough endo-plasmic reticulum decreased and degranulated.The free ribosomes increased.Golgi complexes decreased and their cysts arrayed disorderly and swelled.Lysosomes decreased and lipofuscin increased gradually.The rules of changes of the organelles of the cells treated with AMB were basically the same as those of the control cells in the process of cell aging.However,the degree of change of the former is obviously lighter and the speed of change is also relatively slower.Golgi complexes and centrosomes were especially rich in the cells treated with AMB and they did not show much decrepitude although the cells have aged.Our research mani-fests that AMB has good effects on antiaging and longevity.As a medicine of antiaging and longevity,it should be payed more attention and further exploration.

Key words: Astragalus membranaceous Bunge, human embryonic lung diploid fibroblast, aging