In our previous work, a new lattice-fluid model for binary systems has been developed and successfully applied to ordinary fluid systems, polymer systems and ionic-liquid systems. In this work, the model was further extended to multi-component systems containing ionic liquid based on a multi-component close-packed lattice. Ionic liquids are considered as neutral chain-like molecules, and their characteristic parameters are determined by fitting experimental pVT data of the pure substances. The binary interaction parameters K-ij in the model are obtained by correlating the thermodynamic data of binary systems. It is shown that the vapor-liquid equilibria and the liquid-liquid equilibria of ternary systems containing ionic liquid can be accurately predicted. (C) 2010 Elsevier B.V. All rights reserved.