The synthesis of dimethyl carbonate(DMC) was investigated using four differently supported quaternary ammonium salt catalysts to facilitate their separation after the reaction. The different catalysts are (1) C1 on poly(ST-co-VBC), (2) C2 on poly(ST-DVB-VBC), (3) C3 on macroporous poly(ST-DVB-VBC), (4) C4 on modified MCM-41. The synthesis of DMC was performed in an autoclave under carbon dioxide pressure. The main byproduct was propylene glycol. The immobilized quaternary ammonium salt catalysts showed good catalytic activity for the synthesis of DMC. The order of the reactivity for the catalysts of different support was C1>C3>C2>C4. The catalysts can be reused for four successive runs without considerable loss of their initial reactivity.