The optimum condition for leaching calcined dolomite ore in aqueous hydrochloric acid solutions was determined in this study. The process parameters referred to the acid concentration, the temperature and leaching time. The leaching experiments were performed in a spherical glass batch reactor having a capacity of 1000 mL. The experimental results show that the calcined dolomite ore leaching efficiency increases with addition of acid concentration, temperatur and leaching time increases. The optimum results were achieved at 75 °C for 5 h, and the acid concentration of 2 M HCl. The leaching efficiency of Calcium reached 87.12% while Magnesium dissolved was 85.69% under the above optimal conditions.