Membrane　filtration　has　attracted　surging　attention　for　various　water　treatment　applications,　such　as　oil-water　separation,　because　of　its　low　energy　consumption,　high　separation　efficiency,　and　wide　applicability　for　various　feed　solutions.　The　advances　of　fabricated　membranes　are　often　emphasized　by　high　permeation　flux　and　separation　efficiency.　However,　as　＂membrane-independent　factors＂　(e.g.　filtration　areas　and　pressures)　also　contribute　to　the　variation　of　mass　transfer　during　the　separation,　the　comparison　based　on　the　flux　from　batch　experiments　leads　to　a　pitfall　in　evaluating　the　membrane　performance.　Our　water　permeation　experiments　using　different　set-ups　demonstrate　that　the　permeability　result　are　more　reliable　and　comparable　than　the　flux　value　for　evaluating　membrane　permeation　performance　since　it　considers　the　driving　force　from　either　hydraulic　pressure　or　external　pressure.　However,　flux　and　permeability　may　vary　significantly　among　different　studies,　depending　on　the　selection　of　the　measurement　period　during　the　filtration　experiment.　To　effectively　evaluate　the　mass　transfer　performance,　we　recommend　using　the　permeability　profile　with　a　constant　driving　force.　The　permeability　profile　under　a　constant　driving　force　is　a　desirable　way　to　evaluate　the　membrane　performance,　as　it　can　describe　both　the　mass　transfer　performance　and　the　antifouling　performance　of　a　membrane.　These　key　conclusions　are　drawn　from　oil-water　separation　membranes　but　also　applicable　for　other　pressure-driven　sep-aration　membranes.　This　study　provides　a　guideline　for　effective　membrane　performance　evaluation　by　demonstrating　improved　experimental　and　data　analysis　methods