The effect of dehydrating agent in DMC(dimethyl carbonate) synthesis from methanol and carbon dioxide over Ce_0.8Zr_0.2O₂ catalyst was studied in this work. Ce_0.8Zr_0.2O₂ catalyst having the best activity among Ce_1-xZr_xO₂ catalysts was selected. We could supposed that the addition of dehydrating agents improved the DMC yield by H₂O elimination. When the dehydrating agents such as Na₂SO₄ or K₂SO₄ was added into the synthesis of DMC, the formation amount of DMC increased to about 0.8 ~ 0.9 mmol through the elimination of formed H₂O as by-product.