The effect of beta-alanyl-L-histidinato zinc (AHZ), in which zinc is chelated to beta-alanyl-L-histidine, on bone loss was investigated in the femur of ovariectomized rats. AHZ (10, 30 and 100 mg/kg/d) was orally administered to ovariectomized rats for 3 months. Ovariectomy significantly decreased the estradiol concentration in the serum as compared with that from sham-operated rats. This decrease was not altered by the dose of AHZ. The bone ash weight and mineral density in the femur of ovariectomized rats significantly decreased in comparison with those from sham-operated rats. Moreover, the trabecular bone at the femoral metaphysis was clearly decreased by ovariectomy. The decreases in the femoral ash content and mineral density and the metaphyseal trabecular bone were clearly prevented by the tested doses of AHZ (10, 30 and 100 mg/kg/d). The present finding with histomorphological study further supports the view that the administration of AHZ can prevent bone loss by ovariectomy.