Several acidic ionic liquids (ILs) with different cations and anions were used as catalysts in the transesterification of methyl acetate with n-butanol. The IL [omim][PF6] can enhance the catalytic activity of the partially soluble IL catalyst. The kinetics for the transesterification using the catalysts [HSO(3)bmim][p-TS] and [HSO(3)bmim][OTF] were measured. The ideal homogeneous model and the nonideal homogeneous (NIH) model were used to correlate the kinetic data. The NIH model was more reliable to describe the reaction rate. [GRAPHICS] .