Pervaporation is an efficient membrane process for liquid separation. The past decades had witnessed substantial progress and exciting breakthroughs in both the fundamental and application aspect of pervaporation. This review provided an analytical overview on the potential of pervaporation for separating liquid mixtures in terms of the solubility parameter and the kinetic parameter of solvents. Focus of the review was given to the fundamental understanding of the membrane. Research progress, challenges and opportunities, and the prospect of pervaporation were also discussed. The thermodynamic approach of pervaporation, featuring emphasizing membrane/species interactions, though gained great successes in the past decades, is now facing its toughest challenge in the org-org separation. A kinetic era of pervaporation, featuring emphasizing diffusion selectivity, as well as the synergy between the selective diffusion and sorption, is in the making, and this approach will eventually find solutions to the challenging org-org separation. (c) 2006 Elsevier B.V. All rights reserved.