The standard enthalpy of formation,free energy and thermal capacity of dimethyl carbonate(DMC) were calculated by using the method of Benson group contributions.The thermodynamic data of various syntheses of DMC were compared at different temperatures.The syntheses induded oxidation of methanol or dimethyl ether,reaction of methanol or dimethyl ether with CO_2,and preparations of DMC,DME,formaldehyde and methanol from H_2 and CO.The results showed that the synthesis of DMC by oxidation carbonylation of DME is thermodynamically feasible,but the syntheses of DMC from DME and CO_2 and from methanol and CO_2 and are all thermodynamically unfeasible.These results provided the thermodynamic basis to design the synthesis process and catalyst for DMC.