In　this　paper,　we　prepared　mesoporous　ZnO/SnO2　composite　nanofibers　via　the　electrospinning　technique　using　zinc　acetate　(Zn(OAc)　2)　and　stannic　chloride　pentahydrate　(SnCl4·5H　2O)　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　nanoparticles.　The　nanoparticles　size　increased　with　the　increasing　of　the　calcination　temperature　from　500　to　900　°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　°C　for　5　h,　more　or　less　Zn:Sn　ratios　lowered　the　photocatalytic　efficiency.　A　mechanism　of　the　charge　separation　and　photocatalytic　reaction　for　the　mesoporous　ZnO/SnO　2　composite　nanofibers　was　also　presented.　©　2010　Elsevier　B.V.　All　rights　reserved.