Heat of fusion is an important property for the application of ionic liquids (ILs) as phase change materials. For 40 ionic liquids whose experimental data of fusion heat being available, the lowest energy structure of each ionic liquid is calculated by Gaussian 03 software with B3LYP functional and a 6-31G* basis set. The most effective descriptors were selected by means of stepwise method. Then quantitative structure property relationship (QSPR) models for different types of ILs were developed and evaluated by external datasets. The developed QSPR models can give reasonable correlation and prediction accuracy. (C) 2011 Elsevier B.V. All rights reserved.