Objectives : This study was undertaken to investigate the effects of Amydae Carapax (AC) on parameter related to bone metabolism in ovariectomized rats. Methods : We measured alkaline phosphatase activity and contents of estrogen, calcium, hydroxyproline, osteocalcin, calcitonin and parathyroid hormone after the ovariectomized rats were treated with AC for 30 days. Results : Serum estrogen, calcium and calcitonin contents in ovariectomized rats significantly decreased, but increased after AC treatment. [Significant increase of serum alkaline phosphatase activity, parathyroid hormone activity and osteocalcin content in ovariectomized rats was remarkably decreased by AC treatment. Increase of urinary calcium and hydroxyproline content in ovariectomized rats was decreased by AC treatment.] Conclusions : These results shows that AC has the ability to counteract abnormal calcium metabolic processes due to sex hormone inequality, promoting bone absorption and inhibiting bone formation.