Abstract: The Hansen solubility parameters of ethylene/vinyl aceate copolymer materials and toulene/ethanol mixtures were calculated through the group contribution method. The interaction properties and mutual solubility between polymer and mixtures were analysed,based on the difference of two- or three-dimensional component of solubility parameters. To compare the results of swelling experiment of EVA14 and EVA28, the estimated values were in agreement with experimental data. The membrane was prepared with EVA28 and used for separating toluenl/ethanol mixture, the results show that the membrane was preferential for permeation of toulene. As the mass fraction of toluene was 2%-35% at 25 ℃ in the feed, the toluene flux increased from 55 g·(m ²·h) ^-1 to 900 g·(m ²·h) ^-1 ,and the separation factor decreased from 18 to 4. The results also show that the selectivity and the flux are related to the temperture of the feed. The quasi-equilibrium criteria of pervaporation were compared with VLE of the toluene/ethanol mixture.