This study was undertaken to determine the content of calcium, phosphorus, and magnesium in Korean styled Sagol bone stok (beef leg bone stock) deffering in cooking utensil, cooking method, and cooking time. Cooking was started in cold water and boiling water using stainless steel and aluminium cooker. In the changes of mineral contests in Sagol bone stock at cooking time from 2 to 12 hours, Ca, P, and Mg contents increased significantly by the cooking time in stainless steel and aluminium cooker but Ca and P contents decreased slightly during 12 hours in steel cooker. But Ca, P, and Mg contents of the Sagol bone stock were not significantly different between cooking utensil and method. The extracting rate of Ca, P, and Mg of the Sagol bone stock were $0.02{sim}0.05%$, $0.2{sim}0.7%$, and $0.1{sim}1.0%$, respectively. The extracting rate of Ca was positively correlated with that of Mg (r=0.8872, p<0.001).