Purpose To investigate the prevention eff ec ts of the efficacious part (HUE) of the Caragana sinica from natural on oste oporosis in ovariectomized rats. Methods The imitateion postmenopausal rats model was es tablished by ovariectomomy(OVX) and then HUE was taken once daily with 0.275,0.5 5 g/kg for 3 months,which were contrasted with estrogen group.The bone weight of dry a nd ash,calcium c ontents,bone mineral density,bone biomechanical property,trabecular area,bone mi neral deposition and the biochemistry of serum and urinary related bone metaboli c were measured after the end of therapy. Results Every groups with HUE taken were increa sed more obviously bone mass,bone biomechanical property and trabecular area than the animals of c ontr ol group(P<0.05～0.001),or were increase-trend.The weight of rats uterus wi th HUE were higher than OVX group (P<0.01～0.001)and lower than estrogen group(P<0.001).The level of serum ALP were higher and the urinary Pyd/Cr wa s lower than OVX group. Conclusions The rats of ovariertomized-induced osteopo rosis possess prevention effect treatment with HUE.It possibly possess weak est rogen-like effect to ulerus.