In this study, densities and viscosities of four binary systems {aniline / N, N-dimethylaniline+1- Also, enthalpic and entropic parts of the ∆G *E function were determined, at the same composition, for three studied systems that exhibit complete miscibility, since {aniline + [bmim][OTf]} is a partially miscible system. Considering the calculated thermodynamic properties, molecular interactions in the investigated binary systems were analysed and are discussed.