The research on the isothermal vapor-liquid phase behavior for the ethane (R170) + hexafluoroethane (R 116) system is presented in this paper. The vapor-liquid equilibrium (VLE) data were measured at four temperatures 189.31, 192.63, 247.63 and 252.80 K with an apparatus based on recirculation method. The experimental results were correlated with the Peng-Robinson equation of state using two types of mixing rules, the Panagiotopoulos-Reid mixing rule and the Huron-Vidal mixing rule involving the NRTL model. The calculated data using the regressed parameters were compared with the previous measured results, and good agreements can be observed. (c) 2005 Elsevier B.V. All rights reserved.