In　this　paper,　polyacrylonitrile　(PAN)　porous　membranes　were　prepared　via　combination　of　phase　inversion　and　chemical　reaction　method　with　different　organic　acids　(glacial　acetic　acid,　fumaric　acid　and　citric　acid)　as　additive.　The　experimental　results　showed　that　pure　water　flux　of　the　membrane　decreased　with　increase　in　polymer　concentration　and　membrane　prepared　with　moderate　polymer　concentration　presented　better　performance.　The　influence　of　different　organic　acids　on　the　properties　of　the　casting　solution　was　examined　by　viscosity,　and　the　relationship　between　viscosity　and　membrane　performance　was　analyzed.　The　prepared　membranes　were　characterized　in　terms　of　pure　water　flux,　retention,　pore　size　distribution　and　scanning　electron　microscopy　(SEM)　observation.　It　was　found　that　the　membrane,　prepared　with　glacial　acetic　acid,　has　the　typical　asymmetric　membrane　morphology　with　optimal　combination　of　narrow　pore　size　distribution　and　better　permeability.　The　contribution　of　different　organic　acids　in　casting　solution　to　membrane　performance　during　chemical　reaction　was　quantitatively　analyzed,　and　the　effects　of　different　organic　adds　on　membrane　structures　were　discussed.　Meantime,　compaction　analysis　demonstrated　that　the　membranes　prepared　with　glacial　acetic　acid　had　improvement　in　resistance　against　compaction　compared　to　that　prepared　with　other　acids.　(C)　2013　Elsevier　B.V.　All　rights　reserved.