In this paper, the group contribution Esmaeilzadeh-Roshanfelcr (GC-ER) was used to obtain the group increments for normal boiling point, critical temperature, and critical pressure on the basis of 1775 experimental density data for 294 pure ionic liquids forming 35 groups (28 non-ring groups and 7 group rings) at temperature in the range of 273.15 K-473.15 K and ambient pressure. The average absolute relative deviation (AARD) of the proposed model is 11.49%. For validating the model, density of 53 ionic liquids were predicted and compared with 520 experimental literature density data at different temperatures and ambient pressure that average absolute relative deviation is 9.33%. Also the accuracy of model was compared with the group contribution-Patel Tejja (GC-PT), group contribution-Peng Robbinson (GC-PR), and the group contribution-Van der Waals (GC-VW) model. The results showd that the error of the model is lower than that of the other equations that assess in this work. (C) 2016 Elsevier B.V. All rights reserved.