Numerous　attempts　have　been　made　to　develop　ion-exchange　membranes　with　low　resistance　for　various　applications　such　as　electrodialysis　and　fuel　cells.　In　this　study,　the　strategies　of　immersion　precipitation　and　dry-casting　were　combined,　to　control　the　membrane　porosity　with　the　purpose　of　improving　the　physical　and　electrochemical　properties　of　ion-exchange　membranes.　The　porosity　was　tuned　using　the　time　of　membrane　exposure　to　an　elevated-temperature　environment.　In　addition　to　controlling　the　porosity　to　balance　the　membrane　electrical　resistance　with　the　diffusion　caused　by　the　concentration　gradient,　it　was　experimentally　shown　that　the　porosity　can　influence　the　IEC　and　water　uptake　of　the　membrane　and,　thus,　further　affect　the　resistance.　Furthermore,　the　surface　hydrophilicity　was　characterized　by　water　contact　angle　measurements;　the　results　revealed　that　the　porous　membranes　were　more　hydrophilic　than　the　dense　membranes.　As　demonstrated　by　experimental　data　for　desalination　by　electrodialysis,　it　was　found　that　a　membrane　dried　at　60　°C　for　1　h　had　the　highest　desalination　efficiency.　This　is　mainly　because　porous　membranes　facilitate　the　transport　of　ions.　Compared　to　membranes　with　higher　porosity,　the　membrane　prepared　with　a　1-h　aging　time　had　more　steric　hindrance,　which　can　decrease　the　diffusion　of　ions,　so　that　a　superior　desalination　efficiency　can　be　obtained.　To　further　investigate　the　impact　of　the　density　of　-SO3　2-　functional　groups　on　the　electrodialysis　process,　membranes　with　various　weight　ratios　of　poly(ether　sulfone)　(PES)　to　sulfonated　poly(ether　sulfone)　(SPES)　were　prepared.　With　increasing　content　of　SPES,　the　physical　and　electrochemical　properties　of　the　newly　developed　porous　membranes　were　changed.　A　membrane　with　higher　density　of　functional　groups　was　found　to　have　a　higher　desalination　efficiency,　because　of　the　electrostatic　effect　of　the　membrane.　These　results　were　consistent　with　the　current　efficiency.　Under　optimal　membrane　preparation　conditions,　the　obtained　membrane　had　a　high　IEC　(1.75　mmol/g)　and　water　uptake　(168%).　The　desalination　efficiency　reached　95%,　and　the　current　efficiency　reached　100%.　It　was　concluded　that　the　performance　of　a　porous　membrane　with　controllable　porosity　can　enhance　the　electrodialysis　(ED)　process　with　respect　to　energy　efficiency　and　desalination　efficiency.　New　methods　of　fabricating　membranes　with　pores　such　as　immersion　precipitation　and　dry-casting　are　thought　to　be　potential　routes　to　decreasing　the　electrical　resistance.　©　2017　American　Chemical　Society.