The copolymerization of phenyl glycidyl ether (PGE) and carbon dioxide was performed without any solvent in the presence of ionic liquid as catalyst. 1-alkyl-3-methyl imidazolium salts of different alkyl group (C2, C4, C6) and anions (C1￣, BF4￣, PF6￣) were used for this reaction under constant pressure in a semi-batch reactor. All the 1-alkyl-3-methyl imidazolium chlorides showed good reactivity. The turnover number (TON) of the copolymer was affected by the structure of the imidazolium salt ionic liquid; the one with the cation of longer alkyl chain length and with more nucleophilic anion showed better reactivity. However, TON decreased when hexyl or octyl containing ionic liquids were used probably due to their steric hindrance. The catbonate content and TON of the polycarbonates increased as reaction temperature and carbon dioxide pressure increased.