Nanocrystalline　ternary　wide　band　gap　p-block　metal　semiconductor　ZnGa2O4　was　successfully　prepared　via　a　coprecipitation　method.　The　as-prepared　sample　was　characterized　by　X-ray　diffraction,　N-2-sorption　BET　surface　area,　UV-vis　diffuse　reflectance　spectroscopy,　transmission　electron　microscopy,　high-resolution　transmission　electron　microscopy,　and　Fourier　transformation　infrared　spectroscopy.　ZnGa2O4　showed　superior　photocatalytic　activity　and　stability　for　benzene　degradation　as　compared　to　commercial　TiO2.　However,　its　activity　was　lower　than　another　wide　band　gap　p-block　metal　semiconductor　photocatalyst　Sr2Sb2O7.　The　difference　in　the　photocatalytic　activity　between　ZnGa2O4　and　Sr2Sb2O7　can　be　well　explained　by　their　different　geometric　structures.　This　result　gave　some　new　insight　in　the　development　of　new　ternary　wide　band　gap　p-block　semiconductor　photocatalysts　for　benzene　degradation.