Mg-Al　hydrotalcite-like　compounds　(Mg-Al-HT)　with　Mg/Al　molar　ratio　of　2　have　been　successfully　synthesized　by　a　supersaturated　precipitation　method　and　then　mixed　with　a　titania-sol　to　prepare　nano-crystalline　Mg-Al　hydrotalcite-like　compounds/TiO2　(Mg-Al-HT/TiO2)　heterocompound　photocatalysts　by　a　hydrothermal　method.　The　structure　and　components,　Brunauer-Emmett-Teller　specific　surface　area,　and　photoresponse　of　the　photocatalysts　were　characterized　by　powder　X-ray　diffraction,　transmission　electron　microscopy,　field-emission　scanning　electron　microscopy,　N2　sorption,　and　ultraviolet-visible　diffuse　reflectance　spectroscopy.　The　photocatalytic　activity　of　the　nano-crystalline　Mg-Al-HT/TiO2　heterocompound　photocatalysts　for　degradation　of　benzene　was　superior　to　that　of　single　TiO2　or　Mg-Al-HT　under　365　nm　light　irradiation.　The　Mg-Al-HT/TiO2　heterocompound　photocatalysts　had　higher　stability.　The　electron　paramagnetic　resonance　(EPR)　technique　was　used　to　acquire　the　spin　trapped-EPR　spectra　of　the　active　species　in　the　photocatalytic　reaction.　The　possible　photocatalytic　reaction　mechanism　was　also　proposed.