Objective To explore the effect of Fructus Schisandrae Chinensis on ovariectomy-induced osteoporosis in rats and its functional mechanism.Methods Fifty-nine female Wistar rats were divided into five groups randomly:twelve in the normal control group

twelve in the pseudo-operation group

twelve in the ovariectomy model group

twelve in positive control group

and eleven in the Fructus Schisandrae Chinensis group. One month after bilateral ovariectomy

the rats in the Fructus Schisandrae Chinensis group were administered the decoction of Fructus Schisandrae Chinensis（1g/ml）

and those in the positive control group were administered diethylstilbestrol（0.008mg/ml）. The treatment lasted 3 months with the dosage of 5.6ml/kg. The bone histomorphometric examination was conducted for the bone histomorphometric analysis with the undecalcified sections made from tibia of rats

and the immunocytochemistry method was applied to detect the expression of osteoprotegerin （OPG） of osteoblast （OB） and marrow stromal cells （MSC） and the receptor activator of nuclear factor-κB ligand （RANKL）.Results The percentage of tibial trabecular bone volume in the Fructus Schisandrae Chinensis group was significantly higher than that in the model group. Except for the bony cortex osteoid width

the trabecular bone resorption surface percentage

trabecular bone formation surface percentage

trabecular bone mineralization rate and bony cortex mineralization rate were all significantly lowered than those in the model group; the expression of OPG in OB and MSC was significantly heightened （P<0.05 or P<0.01）; while the expression of RANKL in OB was significantly lowered （P<0.05）.Conclusion One of the functional mechanisms of Fructus Schisandrae Chinensis in the treatment of ovariectomy-induced osteoporosis in rats is to promote the increase of OPG in OB and in MSC secretion to strengthen their combination with RANKL to inhibite the activity of osteoclast.