Quasi-neutral　limit　and　the　boundary　layer　problem　of　the　two/three　dimensional　incompressible　Planck-Nernst-Poisson-Navier-Stokes　equations　for　electro　hydrodynamics　with　the　general　mobilities　of　two　kinds　of　charges　and　in　the　bounded　domain　is　studied.　For　the　generally　smooth　doping　profile　and　the　physical　case　that　the　mobilities　of　two　kinds　of　charges　is　different,　quasi-neutral　limit　with　a　subtle　boundary　layer　structure　is　rigorously　proved　by　constructing　one　new　lambda-weighted　entropy　functional　coupled　with　multi-scaling　approximating　expansion　techniques.　(C)　2019　Elsevier　Inc.　All　rights　reserved.