The　present　investigation　reveals　how　the　surface　morphology　and　the　hydrophobicity　of　polyvinylidene　fluoride　(PVDF)　membranes,　which　were　prepared　via　a　vapor-induced　phase　separation　method,　were　affected　by　the　initial　PVDF　content　in　the　casting　solution　and　the　air　temperature.　The　surface　morphology　was　characterized　with　scanning　electron　microscopy.　A　ternary　phase　diagram　of　PVDF/N,　N-dimethylacetamide/water　was　constructed　to　explain　the　formation　mechanism　of　the　different　morphologies.　The　results　show　that　different　membrane　morphologies　and　hydrophobicities　can　be　obtained　by　changing　the　processing　conditions.　Low　air　temperature　and　high　PVDF　contents　facilitate　the　crystallization　process,　resulting　in　the　formation　of　a　porous　skin　and　particle　morphology,　which　increases　the　hydrophobicity　of　the　surface.　High　air　temperature　and　low　PVDF　contents　are　favorable　for　the　formation　of　a　net-like　surface　morphology　via　spinodal　decomposition　and　lead　to　a　superhydrophobic　surface.　Theoretical　calculations　were　performed　to　testify　that　the　net-like　surface　was　more　favorable　for　superhydrophobicity　than　the　particle-based　surface.　(C)　2012　Elsevier　B.V.　All　rights　reserved.