The effect of superfine grinding process on the physicochemical properties of brown rice flour was studied. Taking the samples of brown rice flour treated with different superfine grinding frequencies of 0～40 as raw materials, the damage starch content, particle size distribution, hydration characteristics and gelatinization properties as indexes, the differences of physicochemical properties of these samples were compared. The results showed that with the increase of crushing frequency, damage starch content of brown rice flour increased from 7.84% to 14.58%; particle size of D［4,3］ decreased from 171μm to 11μm; the water absorption index and swell power increased, water solubility increased at first and then decreased. The results of RVA showed that peak viscosity, trough viscosity, breakdown value, final viscosity and setback increased, initial gelatinization temperature decreased. The results of scanning electron microscopy showed that the starch granules were crushed to form irregular fractionlet with pits on the surface.