In(　OH)　3　photocatalyst　was　prepared　using　ultrasonic　hydrolysis　precipitation　followed　by　calcining　at　temperature　lower　than　160　T.　The　characterizations　by　XRD,　DRS,　TG-DSC,　TEM　and　FTIR　show　that　the　solid　is　a　cubic　crystal　with　10-15　nm　size,　and　has　two　band　gaps,　direct　band　gap　5.48　and　indirect　gap　5.02　eV.　Evaluation　of　the　photocatalytic　activity　toward　oxidation　reactions　of　benzene　under　UV　irradiation　(lambda(max)　=　254　nm)　showed　that　In(OH)(3)　presented　much　higher　photoactivity　and　active　stability　than　commercial　Degussa-P25　TiO2.　FTIR　characterization　for　the　samples　before　and　after　the　photocatalytic　reaction　suggested　that　the　better　photocatalytic　behavior　of　In(OH)(3)　than　the　TiO2　is　due　to　lower　aggradations　of　the　intermediate　species　on　its　surface　in　photocatalytic　process.