MgO and CaO prepared from the dissociation of basic magnesium carbonate and calcium carbonate at elevated temperature were used to investigate the effect of base strength and basicity on the synthesis of dimethyl carbonate (DMC) from propylene carbonate (PC) and methanol (MeOH). It was found that the rise of base strength could reduce the temperature needed for this reaction remarkably. On the other hand, with the increase of the amount of base site, the reaction rate rises but DMC selectivity decreases. (C) 2003 Elsevier Science B.V. All rights reserved.