The　coupled　nanocrystalline　ZnO/ZnS　was　fabricated　and　immobilized　in　Nafion　membrane　by　using　sodium　sulfide　(Na2S)　as　the　single　anion　precursor.　The　molar　ratio　of　ZnO　to　ZnS　can　be　controlled　by　simply　adjusting　the　reaction　time.　The　as-prepared　ZnO/ZnS-Nafion　samples　were　characterized　by　various　methods,　including　optical　absorption,　X-ray　diffraction　and　high-resolution　transmission　electron　microscopy.　These　coupled　ZnO/ZnS　nanocrystals　embedded　in　Nation　membrane　displayed　excellent　photocatalytic　activities　for　their　efficient　charge　separation　properties.　A　mechanism　of　ZnO/ZnS　nanoparticle　fabrication　in　Nafion　was　deduced　from　the　solubility　difference,　and　the　photocatalytic　mechanism　of　coupled　ZnO/ZnS　was　discussed　as　well.