In　this　paper,　we　prepared　mesoporous　ZnO/SnO2　composite　nanofibers　via　the　electrospinning　technique　using　zinc　acetate　(Zn(OAc)(2))　and　stannic　chloride　pentahydrate　(SnCl4　center　dot　5H(2)O)　as　precursors,　cellulose　acetate　(CA)　as　the　fiber　template,　and　N,N-dimethylformamide　(DMF)/acetone　(1:1,　v/v)　as　the　co-solvent.　The　structure　and　morphology　of　composite　nanofibers　were　characterized　by　scanning　electron　microscopy　(SEM),　transmission　electron　microscopy　(TEM),　X-ray　diffraction　(XRD),　UV-vis　diffuse　reflectance　spectroscopy　(DRS)　and　nitrogen　adsorption-desorption　isotherm　analysis.　TEM　images　showed　that　the　mesoporous　ZnO/SnO2　composite　nanofibers　were　composed　of　grain-like　nanopartides.　The　nanoparticles　size　increased　with　the　increasing　of　the　calcination　temperature　from　500　to　900　degrees　C.　Moreover,　the　crystal　phases,　grain　sizes,　and　band　gap　energy　of　the　mesoporous　ZnO/SnO2　composite　nanofibers　were　influenced　by　the　molar　ratio　of　Zn:Sn　and　the　calcination　temperatures.　The　photocatalytic　activity　of　the　mesoporous　ZnO/SnO2　composite　nanofibers　toward　the　decomposition　of　Rhodamine　B　(RhB)　was　investigated.　It　was　found　that　the　photocatalytic　activity　of　the　mesoporous　ZnO/SnO2　composite　nanofibers　was　dependant　on　their　surface　areas,　light　utilization　efficiency,　and　the　separation　of　photogenerated　electron/hole　pairs.　The　maximum　photocatalytic　activity　was　shown　for　composite　nanofibers　with　the　molar　ratio　of　Zn:Sn　2:1　and　calcination　at　500　degrees　C　for　5h.　more　or　less　Zn:Sn　ratios　lowered　the　photocatalytic　efficiency.　A　mechanism　of　the　charge　separation　and　photocatalytic　reaction　for　the　mesoporous　ZnO/SnO2　composite　nanofibers　was　also　presented.　(C)　2010　Elsevier　B.V.　All　rights　reserved.