Zn-doped　Bi-Mo　complex　metal　oxide　photocatalysts　were　prepared　via　hydrothermal　process.　The　prepared　samples　were　characterized　by　X-ray　powder　diffraction　and　UV-vis　diffuse　reflectance　spectroscopy.　The　results　display　that　Zn　doping　can　not　alter　the　crystal　form　of　the　complex　metal　oxide　and　the　band　gap　of　the　samples　are　all　about　2.56　eV.　The　photocatalytic　activity　of　the　samples　for　the　decomposition　of　Rhodamine　B　under　visible　light　irradiation　shows　that　the　concentration　of　Zn2+　has　great　effect　on　the　photocatalytic　activity　and　the　best　photocatalytic　activity　is　obtained　by　the　sample　with　0.6%　Zn　doping　amount.　©　(2011)　Trans　Tech　Publications,　Switzerland.