Abstract: The paper introduces the major reason on flotation behaviour difference of diaspore and gangue mineral.And in the experimental investigation on revese flotation,BS-1 and TZ-1 is used to treat with bauxite including a great deal of gangue under a moderately acidic condition,finally,the A/S on concentrate gets to 10.05,the recovery on concentrate is 70.95%.The A/S(2.32) on flotation final tailings is lower than the A/S(2.34) on surface rock.