In order to examine the effects of Kami-kihi-to (KKT or Jia-Wei-Gui-Pi-Tang) on osteopenia, we measured bone mineral density using computed X-ray absorptometry and monitored metabolism and bone tissue in an ovariectomized (OVX) rat model. Bone mineral density was significantly lower in the OVX group than in normal group 3 months after ovariectomy. However, the bone mineral density of the OVX group administered KKT was clearly higher than that of the untreated OVX group. Locomotor activity was regular in the normal group and in the OVX groups before administration of KKT. After 6-month administration of KKT, in OVX groups, the pattern of locomotor activity became diphasic with clear active and resting phases, as was also observed in the normal group. The locomotor activity did not decrease in the OVX groups after administration of KKT. At 6 months, the continuity of the trabecular bone was higher in the OVX group administered KKT than in the untreated OVX group. These results indicate that KKT improved the menopausal symptoms and increased the locomotor activity of the OVX group, thereby increasing bone mineral density.