The purpose of this study was to evaluate the effects of ovariectomy, the influences of estrogen replacement therapy and / or suplemen CavitD3 on mandible's calsium contents of animal's models. Forty-five female rats were used in this researched. Five rats were sacrificed for unoperated basal controls and the others were bilaterally ovariectomized. The ovariectomized animals were devided into 8 groups and two of these groups were only ovariectomized, the others were treated by estrogen replacement therapy. CavitD3 and combination of both per oral for 2 and 4 weeks and then were sacrificed. Mandible's calsium contents were analyzed by Ion Selective Electrode methode after demineralized with 10% phosphoric acid for 24 hours. Result : there were significant increased of mandible's calcium content at 2 weeks post-ovariectomy, but the results decreased at 4 weeks post-ovariectomy. Estrogen replacement therapy and treated with CavitD3 for 2 and 4 weeks or combination of both for 2 weeks increased the mandible's calsium contents of ovariectomized rats, but therapy combination with estrogen and CavitD3 for 4 weeks had a protective effect to mandible's calsium contents of ovariectomized rats.