Multiester-appended imidazolium ionic liquids were synthesized in a quatemization reaction between the imidazole derivatives carrying single or double esters and ethyl chloroacetate or bromoethane. Multicarboxylic-appended imidazolium ionic liquids were achieved from the hydrolysis of the corresponding ionic liquids. The influences of multifunctional groups on the transition temperatures and viscosity of these new ionic liquids were investigated.