Aging is characterized by an age-dependent reduction in bone density. Pronounced bone loss by postmenopausal estrogen deficiency induces a bad effect on dynamic balance of bone metabolism. When the bone density is reduced to the level below the fracture threshold, the risk for fracture is greatly increased. The purpose of this study is to examine what are the effects of the Guisinhwan(GSH : 歸腎丸) on the ovariectomized rat model of postmenopausal osteoporosis. The results of the experiment are as follows: Body weight in control group showed significant increase in comparison with sham, but that in GSH-treated showed no change in comparison with control. The level of serum albumin in control group showed significant decrease in comparison with sham. That in GSH-treated was slightly decreased in comparison with control. The level of serum ALP activity in control group showed significant increase in comparison with sham, but that in GSH-treated was significantly decreased in comparison with control. The level of serum phosphorous, calcium, GOT, GPT, T3 did not significant change among the three groups. The level of serum estrogen in control group showed slightly decreased in comparison with sham, but that in GSH-treated showed no change in comparison with control. The level of serum T4 in control group showed significant increase in comparison with sham, but that in GSH-treated was significantly decreased in comparison with control. Trabecular bone area as well as trabecular thickness in control group showed significant decrease In comparison with sham. Those in GSH-treated showed significant increase in comparison with control. Trabecular number did not significant change among the three groups. Trabecular separation only in GSH-treated showed significant decrease in comparison with control. Osteoclast number in control group showed significant increase in comparison with sham. That in GSH-treated showed significant decrease in comparison with control. Oseoblast surface in control group showed significant increase in comparison with sham, but that in GSH-treated showed no change in comparison with control. According to the above these results, GSH has shown to be capable of preventing and curing osteoporosis caused by old-aged and postmenopause.