This work presents sintering experiments of MgO doped with 0 to 5 mol% sintering additives. Dense MgO ceramics (>99%) were obtained with sintering additives at sintering temperatures as low as 1640 degrees C. The sintering additives can lower the sintering temperature and the open porosity. After corroded in 1050 degrees C molten salt for 30 min, the samples show good anti-corrosion ability.