Synthesis of methyl ethyl carbonate(MEC) by transesterification of diethyl carbonate(DMC) with dimethyl carbonate(DEC) was carried out over Al_2O_3/SiO_2 catalysts.Effects of the active component loading amount,catalyst dosage,reaction temperature and time on the transesterification reaction were investigated in detail.The catalysts were characterized by means of NH_3-TPD and N_2 adsorption/desorption techniques.Results indicated that the 12% Al_2O_3/SiO_2 catalyst exhibited the best activity for the transesterification of DMC with DEC.Under the optimial conditions: catalyst dosage 7%,temperature 120 ℃, reaction time 8 h,molar ratio of DMC to DEC 1∶1,the highest yield of MEC,about 63.64%,was obtained.Furthermore,the reusability of the catalyst was also investigated.The catalyst exhibited a good stability for transesterification of DMC with DEC under the reaction conditions.