The　harvesting　of　the　energy　stored　in　the　salinity　gradient　between　seawater　and　river　water　by　a　membrane-scale　nanofluidic　diode　for　sustainable　generation　of　electricity　is　attracting　significant　attention　in　recent　years.　However,　the　performance　of　previously　reported　nanofluidic　diodes　is　sensitive　to　the　pH　conditions,　which　restricts　their　potential　applications　in　wider　fields　with　variable　pH　values.　Herein,　a　pH-resistant　membrane-scale　nanofluidic　diode　with　a　high　ion　rectification　ratio　of　approximate　to　85　that　demonstrates　a　stable　ion　rectification　property　over　a　wider　pH　range　from　4　to　10　is　reported.　This　pH-resistant　ion　rectification　is　explained　quantitatively　by　a　theoretical　calculation　based　on　the　Poisson　and　Nernst-Plank　equations.　The　nanofluidic　diode　membrane　is　integrated　into　a　power　generation　device　to　harvest　the　energy　stored　in　the　salinity　gradient.　By　mixing　the　simulated　seawater　(0.5mKCl)　and　river　water　(0.01mKCl)　through　the　membrane,　the　device　outputs　an　impressive　power　density　of　3.15Wm(-2)　and　demonstrates　high　stability　over　a　wider　pH　range.　The　membrane-scale　nanofluidic　diode　provides　a　pH-resistant　platform　to　control　the　ion　transport　and　to　convert　the　salinity　gradient　into　electric　energy.